fix query failure on Django 1.3 or earlier

Author: michiya

sql_server/pyodbc/compiler.py

@@ -92,7 +92,7 @@ def as_sql(self, with_limits=True, with_col_aliases=False):
         result.extend(from_)
         params.extend(f_params)
 
-        if self.query.select_for_update and self.connection.features.has_select_for_update:
+        if self.connection.features.has_select_for_update and self.query.select_for_update:
             # If we've been asked for a NOWAIT query but the backend does not support it,
             # raise a DatabaseError otherwise we could get an unexpected deadlock.
             nowait = self.query.select_for_update_nowait