[1.5.x] Fixed #18989 -- Removed unused condition in CursorWrapper

Thanks zimnyx for the report.
Backport of 8c6927876 from master.

django/db/backends/util.py

@@ -24,10 +24,8 @@ class CursorWrapper(object):
             self.db.set_dirty()
 
     def __getattr__(self, attr):
+        if attr in ('execute', 'executemany', 'callproc'):
             self.set_dirty()
-        if attr in self.__dict__:
-            return self.__dict__[attr]
-        else:
         return getattr(self.cursor, attr)
 
     def __iter__(self):