Use EventGsonProvider from Gerrit core

EventGsonProvider has been moved to Gerrit core.
Use it instead of the events-broker version.

Bug: Issue 14460
Change-Id: If445cd49cde65a3d51fd2f3a26743aa7dee5d81e
diff --git a/src/main/java/com/googlesource/gerrit/plugins/pubsub/Module.java b/src/main/java/com/googlesource/gerrit/plugins/pubsub/Module.java
index 32110dd..82e6133 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/pubsub/Module.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/pubsub/Module.java
@@ -14,11 +14,11 @@
 
 package com.googlesource.gerrit.plugins.pubsub;
 
-import com.gerritforge.gerrit.eventbroker.EventGsonProvider;
 import com.google.api.gax.core.CredentialsProvider;
 import com.google.gerrit.extensions.config.FactoryModule;
 import com.google.gerrit.extensions.events.LifecycleListener;
 import com.google.gerrit.extensions.registration.DynamicSet;
+import com.google.gerrit.server.events.EventGsonProvider;
 import com.google.gerrit.server.events.EventListener;
 import com.google.gson.Gson;
 import com.google.inject.Inject;