Stop calling unregisterWorkqueue which was removed in gerrit

Change-Id: Iebf478ff701da4dcdc063cb0c96684ce85b6964b
diff --git a/src/main/java/com/ericsson/gerrit/plugins/eventslog/EventQueue.java b/src/main/java/com/ericsson/gerrit/plugins/eventslog/EventQueue.java
index cdb3fb9..035378e 100644
--- a/src/main/java/com/ericsson/gerrit/plugins/eventslog/EventQueue.java
+++ b/src/main/java/com/ericsson/gerrit/plugins/eventslog/EventQueue.java
@@ -42,7 +42,6 @@
   @Override
   public void stop() {
     if (pool != null) {
-      pool.unregisterWorkQueue();
       pool = null;
     }
   }