Bug 224327 if domain.com is blocked, sub.domain.com is blocked, but cannot be unblocked using remove

patch by mconnor@myrealbox.com r=neil sr=alecf

suite/common/permissions/cookieViewer.js

@@ -526,7 +526,10 @@ function setCookiePermissions(action) {
                             .getService(Components.interfaces.nsIIOService);
   var uri = ioService.newURI(url, null, null);
   
-  permissionmanager.add(uri, dialogType, action);
+  // only set the permission if the permission doesn't already exist
+  if (permissionmanager.testPermission(uri, dialogType) != action)
+    permissionmanager.add(uri, dialogType, action);
+
   site.focus();
   site.value = "";
 }