Remove Google as a SSO service.

web/react/utils/constants.jsx

@@ -60,7 +60,6 @@ module.exports = {
   DEFAULT_CHANNEL: 'town-square',
   OFFTOPIC_CHANNEL: 'off-topic',
   GITLAB_SERVICE: 'gitlab',
-  GOOGLE_SERVICE: 'google',
   EMAIL_SERVICE: 'email',
   POST_CHUNK_SIZE: 60,
   MAX_POST_CHUNKS: 3,