Fix warnings doc-string

Author: tsift

python/lib/sift_client/resources/rules.py

@@ -280,7 +280,7 @@ async def batch_update_or_create_rules(
             override_expression_validation: When true, the rules will be created even if the expressions are invalid.
 
         Warnings:
-            UserWarning: If not all rules are created or updated.
+            SiftWarning: If not all rules are created or updated.
 
         Returns:
             List of updated or created Rules.