Followup for bug 945753 - fix copy-paste mistake in making Australis set currentset correctly, rs=trivial

--HG--
extra : rebase_source : ce45fd2a89a7060c5f87a7f53cd84ae5d81643bd

browser/components/customizableui/src/CustomizableUI.jsm

@@ -866,7 +866,7 @@ let CustomizableUIInternal = {
     this.insertWidgetBefore(widgetNode, nextNode, insertionContainer, areaId);
 
     if (gAreas.get(areaId).get("type") == CustomizableUI.TYPE_TOOLBAR) {
-      areaNode.setAttribute("currentset", gPlacements.get(areaId).join(','));
+      aAreaNode.setAttribute("currentset", gPlacements.get(areaId).join(','));
     }
   },