chore(deps): update jetty packages to v9.4.29.v20200521 (GoogleCloudPlatform#2964)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| org.eclipse.jetty:jetty-maven-plugin | patch | `9.4.28.v20200408` -> `9.4.29.v20200521` |
| [org.eclipse.jetty:apache-jsp](http://www.eclipse.org/jetty) | patch | `9.4.28.v20200408` -> `9.4.29.v20200521` |
| [org.eclipse.jetty:jetty-annotations](http://www.eclipse.org/jetty) | patch | `9.4.28.v20200408` -> `9.4.29.v20200521` |
| [org.eclipse.jetty:jetty-util](http://www.eclipse.org/jetty) | patch | `9.4.28.v20200408` -> `9.4.29.v20200521` |
| [org.eclipse.jetty:jetty-webapp](http://www.eclipse.org/jetty) | patch | `9.4.28.v20200408` -> `9.4.29.v20200521` |
| [org.eclipse.jetty:jetty-util-ajax](http://www.eclipse.org/jetty) | patch | `9.4.28.v20200408` -> `9.4.29.v20200521` |
| [org.eclipse.jetty:jetty-client](http://www.eclipse.org/jetty) | patch | `9.4.28.v20200408` -> `9.4.29.v20200521` |
| [org.eclipse.jetty:jetty-server](http://www.eclipse.org/jetty) | patch | `9.4.28.v20200408` -> `9.4.29.v20200521` |

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appengine-java11/appengine-simple-jetty-main/pom.xml

@@ -29,30 +29,30 @@
     <dependency>
       <groupId>org.eclipse.jetty</groupId>
       <artifactId>jetty-server</artifactId>
-      <version>9.4.28.v20200408</version>
+      <version>9.4.29.v20200521</version>
     </dependency>
     <dependency>
       <groupId>org.eclipse.jetty</groupId>
       <artifactId>jetty-webapp</artifactId>
-      <version>9.4.28.v20200408</version>
+      <version>9.4.29.v20200521</version>
       <type>jar</type>
     </dependency>
     <dependency>
       <groupId>org.eclipse.jetty</groupId>
       <artifactId>jetty-util</artifactId>
-      <version>9.4.28.v20200408</version>
+      <version>9.4.29.v20200521</version>
     </dependency>
     <dependency>
       <groupId>org.eclipse.jetty</groupId>
       <artifactId>jetty-annotations</artifactId>
-      <version>9.4.28.v20200408</version>
+      <version>9.4.29.v20200521</version>
       <type>jar</type>
     </dependency>
     <!-- extra explicit dependency needed because there is a JSP in the sample-->
     <dependency>
       <groupId>org.eclipse.jetty</groupId>
       <artifactId>apache-jsp</artifactId>
-      <version>9.4.28.v20200408</version>
+      <version>9.4.29.v20200521</version>
     </dependency>
   </dependencies>
   <!-- [END gae_java11_server_dependencies] -->

appengine-java11/gaeinfo/pom.xml

@@ -118,7 +118,7 @@ Copyright 2019 Google LLC
       <plugin>
         <groupId>org.eclipse.jetty</groupId>
         <artifactId>jetty-maven-plugin</artifactId>
-        <version>9.4.28.v20200408</version>
+        <version>9.4.29.v20200521</version>
       </plugin>
     </plugins>
 

appengine-java11/guestbook-cloud-firestore/pom.xml

@@ -104,7 +104,7 @@
       <plugin>
         <groupId>org.eclipse.jetty</groupId>
         <artifactId>jetty-maven-plugin</artifactId>
-        <version>9.4.28.v20200408</version>
+        <version>9.4.29.v20200521</version>
       </plugin>
 
       <plugin>

appengine-java11/oauth2/pom.xml

@@ -109,7 +109,7 @@
         <plugin>
           <groupId>org.eclipse.jetty</groupId>
           <artifactId>jetty-maven-plugin</artifactId>
-          <version>9.4.28.v20200408</version>
+          <version>9.4.29.v20200521</version>
         </plugin>
 
         <plugin>

appengine-java8/sendgrid/pom.xml

@@ -70,7 +70,7 @@ Copyright 2018 Google LLC
       <plugin>
         <groupId>org.eclipse.jetty</groupId>
         <artifactId>jetty-maven-plugin</artifactId>
-        <version>9.4.28.v20200408</version>
+        <version>9.4.29.v20200521</version>
       </plugin>
     </plugins>
   </build>

appengine-java8/spanner/pom.xml

@@ -83,7 +83,7 @@
       <plugin>
         <groupId>org.eclipse.jetty</groupId>
         <artifactId>jetty-maven-plugin</artifactId>
-        <version>9.4.28.v20200408</version>
+        <version>9.4.29.v20200521</version>
       </plugin>
       <!-- END -->
 

cloud-sql/mysql/servlet/pom.xml

@@ -81,7 +81,7 @@
       <plugin>
         <groupId>org.eclipse.jetty</groupId>
         <artifactId>jetty-maven-plugin</artifactId>
-        <version>9.4.28.v20200408</version>
+        <version>9.4.29.v20200521</version>
         <configuration>
           <scanIntervalSeconds>1</scanIntervalSeconds>
         </configuration>

cloud-sql/postgres/servlet/pom.xml

@@ -71,7 +71,7 @@
       <plugin>
         <groupId>org.eclipse.jetty</groupId>
         <artifactId>jetty-maven-plugin</artifactId>
-        <version>9.4.28.v20200408</version>
+        <version>9.4.29.v20200521</version>
         <configuration>
           <scanIntervalSeconds>1</scanIntervalSeconds>
         </configuration>

endpoints/getting-started/pom.xml

@@ -75,7 +75,7 @@
       <plugin>
         <groupId>org.eclipse.jetty</groupId>
         <artifactId>jetty-maven-plugin</artifactId>
-        <version>9.4.28.v20200408</version>
+        <version>9.4.29.v20200521</version>
       </plugin>
     </plugins>
   </build>

endpoints/multiple-versions/pom.xml

@@ -39,7 +39,7 @@
     <maven.war.plugin>2.6</maven.war.plugin>
 
     <appengine.maven.plugin>2.2.0</appengine.maven.plugin>
-    <jetty.maven.plugin>9.4.28.v20200408</jetty.maven.plugin>
+    <jetty.maven.plugin>9.4.29.v20200521</jetty.maven.plugin>
 
     <failOnMissingWebXml>false</failOnMissingWebXml> <!-- REQUIRED -->
   </properties>