Fix broken imports in redis/__init__.pyi

This is needed by #786.

third_party/2/redis/__init__.pyi

@@ -2,10 +2,10 @@
 #
 # NOTE: This dynamically typed stub was automatically generated by stubgen.
 
-import redis.client
-import redis.connection
-import redis.utils
-import redis.exceptions
+from . import client
+from . import connection
+from . import utils
+from . import exceptions
 
 Redis = client.Redis
 StrictRedis = client.StrictRedis