Stop using WorkQueue#unregisterWorkQueue

Change-Id: Iaa6784586a1bb4b4a7b4c9b900d35aeb84af61d5

src/main/java/com/googlesource/gerrit/plugins/hooks/HookQueue.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/HookQueue.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookQueue.java
index 6a5e33e..e1352b4 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/hooks/HookQueue.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookQueue.java
@@ -48,7 +48,6 @@
   @Override
   public void stop() {
     if (queue != null) {
-      queue.unregisterWorkQueue();
       queue.shutdownNow();
       queue = null;
     }