We implemented a window to during shutdown.
While this window is displayed,
the blockchain is during process to database terminating.
https://github.com/FromHDDtoSSD/SorachanCoin-qt/commit/471266c9b58b4b5ef07d41e7bd9b3fe4fa2c3fcd
chapter290, [SORA][SORA Network] We implemented a window to during shutdown.
