message: fix a thread safety analysis warning
diff: @@ -329,7 +329,7 @@ private:
  SyncSession(_impl::SyncClient&, std::shared_ptr<DB>, SyncConfig, SyncManager* sync_manager);
  void download_fresh_realm(util::Optional<SyncError::ClientResetModeAllowed> allowed_mode)
  - REQUIRES(!m_config_mutex, !m_state_mutex);
  + REQUIRES(!m_config_mutex, !m_state_mutex, !m_connection_state_mutex);
  void handle_fresh_realm_downloaded(DBRef db, util::Optional<std::string> error_message,
  util::Optional<SyncError::ClientResetModeAllowed> allowed_mode)
  REQUIRES(!m_state_mutex, !m_config_mutex, !m_connection_state_mutex);
  