Hotfix schema version on auth

Author: denis-ignatenko

tarantool/connection.py

@@ -433,6 +433,7 @@ def authenticate(self, user, password):
         if not self._socket:
             return self._opt_reconnect()
 
+        self.schema_version = 0
         request = RequestAuthenticate(self, self._salt, self.user,
                                       self.password)
         auth_response = self._send_request_wo_reconnect(request)