Call .sync_updates on .connect iff exported_auth is None

Calling this method on exported clients would trigger a
UserMigrateError because it was being used on a non-native
data center. For .connects like this, don't attempt syncing
updates.

telethon/telegram_bare_client.py

@@ -201,8 +201,11 @@ class TelegramBareClient:
                     self(GetConfigRequest()).dc_options
 
             # Connection was successful! Try syncing the update state
+            # IF we don't have an exported authorization (hence we're
+            # not in our NATIVE data center or we'd get UserMigrateError)
             # to also assert whether the user is logged in or not.
             self._user_connected = True
+            if not exported_auth:
                 try:
                     self.sync_updates()
                     self._set_connected_and_authorized()