Suppress Edit Assignee button in the GWT UI

This action is already handled by the "edit" button next to Assignee.

Change-Id: Ie3da9b49f4fad89af2fde9569ab4d24b8651f9ff
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Actions.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Actions.java
index e7e4819..779c32b 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Actions.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Actions.java
@@ -37,6 +37,7 @@
 class Actions extends Composite {
   private static final String[] CORE = {
     "abandon",
+    "assignee",
     "cherrypick",
     "description",
     "followup",