Upgrade error_prone_core to 2.3.4

Change-Id: I7e91acc4d094d92cac41d5044268dfc2208bb663
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

org.eclipse.jgit.benchmarks/pom.xml

@@ -124,7 +124,7 @@
           <dependency>
             <groupId>com.google.errorprone</groupId>
             <artifactId>error_prone_core</artifactId>
-            <version>2.3.3</version>
+            <version>2.3.4</version>
           </dependency>
         </dependencies>
       </plugin>

pom.xml

@@ -890,7 +890,7 @@
               <dependency>
                 <groupId>com.google.errorprone</groupId>
                 <artifactId>error_prone_core</artifactId>
-                <version>2.3.3</version>
+                <version>2.3.4</version>
               </dependency>
             </dependencies>
           </plugin>