Fix typo in deprecation message

The message recommended using `authTwitterUsingUserID` (note that the
`ID` at the end of the method name is all capitalized).

However, the actual method name is `authTwitterUsingUserId` (note the `Id` at the
end).

yesod-auth-oauth/Yesod/Auth/OAuth.hs

@@ -130,7 +130,7 @@ authTwitter :: YesodAuth m
             -> ByteString -- ^ Consumer Secret
             -> AuthPlugin m
 authTwitter key secret = authTwitter' key secret "screen_name"
-{-# DEPRECATED authTwitter "Use authTwitterUsingUserID instead" #-}
+{-# DEPRECATED authTwitter "Use authTwitterUsingUserId instead" #-}
 
 -- | Twitter plugin which uses Twitter's /user_id/ as ID.
 --