sql_catalog: No need to check for type

In case uid=0, its already being treated as int, so there is no
need to check for type and add time to performance.

product/ZSQLCatalog/SQLCatalog.py

@@ -1497,9 +1497,8 @@ class Catalog(Folder,
 
     for object in object_list:
       uid = getattr(aq_base(object), 'uid', None)
-      # Several Tool objects have uid=0 (not 0L) from the beginning, but
-      # we need an unique uid for each object.
-      if uid is None or isinstance(uid, int) and uid == 0:
+      # Generate unique uid for object having 0 or None as uid
+      if uid is None or uid == 0:
         try:
           object.uid = self.newUid()
         except ConflictError: