Upgrade rxjava 2.1.16

Author: slandelle

pom.xml

@@ -408,7 +408,7 @@
     <activation.version>1.2.0</activation.version>
     <netty-reactive-streams.version>2.0.0</netty-reactive-streams.version>
     <rxjava.version>1.3.8</rxjava.version>
-    <rxjava2.version>2.1.14</rxjava2.version>
+    <rxjava2.version>2.1.16</rxjava2.version>
     <logback.version>1.2.3</logback.version>
     <testng.version>6.13.1</testng.version>
     <jetty.version>9.4.8.v20171121</jetty.version>