File "electrum/gui/qt/main_window.py", line 3165, in closeEvent
  File "electrum/gui/qt/main_window.py", line 3192, in clean_up
  File "electrum/gui/qt/__init__.py", line 385, in close_window
  File "electrum/daemon.py", line 530, in stop_wallet
  File "concurrent/futures/_base.py", line 435, in result
  File "concurrent/futures/_base.py", line 384, in __get_result
  File "electrum/wallet.py", line 381, in stop
  File "electrum/wallet.py", line 315, in save_db
  File "electrum/wallet_db.py", line 1344, in write
  File "electrum/util.py", line 412, in <lambda>
  File "electrum/util.py", line 408, in do_profile
  File "electrum/wallet_db.py", line 1354, in _write
  File "electrum/storage.py", line 84, in write