messageTray: Fix going to left-click/right-click on the same summary item

This code was originally here to close the summary box pointer if it was
already open, but it seems that it isn't necessary, and is causing all
sorts of problems.

js/ui/messageTray.js

@@ -2356,9 +2356,6 @@ const MessageTray = new Lang.Class({
         this._summaryBoxPointerState = State.HIDING;
         this._unlock();
 
-        if (this._summaryBoxPointerItem == this._clickedSummaryItem)
-            this._setClickedSummaryItem(null);
-
         if (this._summaryBoxPointerItem.source.notifications.length == 0) {
             this._summaryBoxPointer.actor.hide();
             this._hideSummaryBoxPointerCompleted();