Fix JS strict warning. Bug 230645, patch by Alex Vincent <ajvincent@juno.com>,

r=timeless, sr=bzbarsky

xpfe/components/prefwindow/resources/content/pref-advanced.xul

@@ -288,7 +288,7 @@
 
       getCurrentJVMConfig : function() {
         return this.currentJVMConfig;
-      },
+      }
     };
 
     function setVisible(visible) {