Add ttl argument to redis client set operation (#4788)

third_party/2and3/redis/client.pyi

@@ -183,6 +183,7 @@ class Redis(object):
         px: Union[None, int, timedelta] = ...,
         nx: bool = ...,
         xx: bool = ...,
+        keepttl: bool = ...,
     ) -> Optional[bool]: ...
     def __setitem__(self, name, value): ...
     def setbit(self, name: _Key, offset: int, value: int) -> int: ...