Reduce visibility of SyncEventBroker to package-private

All the classes in this plugin are package-private because they are not
meant to be used outside of this plugin. Change SyncEventBroker
visibility to be consistent.

Change-Id: Icb526e78659076202a657c1d6394d46d36308a3c

src/main/java/com/ericsson/gerrit/plugins/syncevents/SyncEventBroker.java

diff --git a/src/main/java/com/ericsson/gerrit/plugins/syncevents/SyncEventBroker.java b/src/main/java/com/ericsson/gerrit/plugins/syncevents/SyncEventBroker.java
index 5414c9d..36cfc15 100644
--- a/src/main/java/com/ericsson/gerrit/plugins/syncevents/SyncEventBroker.java
+++ b/src/main/java/com/ericsson/gerrit/plugins/syncevents/SyncEventBroker.java
@@ -25,10 +25,10 @@
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 
-public class SyncEventBroker extends EventBroker {
+class SyncEventBroker extends EventBroker {
 
   @Inject
-  public SyncEventBroker(DynamicSet<UserScopedEventListener> listeners,
+  SyncEventBroker(DynamicSet<UserScopedEventListener> listeners,
       DynamicSet<EventListener> unrestrictedListeners,
       ProjectCache projectCache,
       Factory notesFactory,