don't return, update docstring

Author: trel

irods/manager/zone_manager.py

@@ -43,12 +43,7 @@ def remove(self, zone_name):
         logger.debug(response.int_info)
 
     def modify(self, zone_name, attribute, value):
-        """
-        Modify a zone attribute.
-
-        Returns:
-            The modified zone.
-        """
+        """Modify a zone attribute."""
         if attribute == "connection":
             attribute = "conn"  # server expects this string
         message_body = GeneralAdminRequest("modify", "zone", zone_name, attribute, value)
@@ -57,4 +52,3 @@ def modify(self, zone_name, attribute, value):
             conn.send(request)
             response = conn.recv()
         logger.debug(response.int_info)
-        return self.get(zone_name)