Upgrade lombok 1.18.12

Author: slandelle

extras/retrofit2/pom.xml

@@ -13,7 +13,7 @@
 
   <properties>
     <retrofit2.version>2.5.0</retrofit2.version>
-    <lombok.version>1.18.6</lombok.version>
+    <lombok.version>1.18.12</lombok.version>
     <javaModuleName>org.asynchttpclient.extras.retrofit2</javaModuleName>
   </properties>