Suggestion: Change quit icon to use power off sign

[jonashaag]

Currently the quit icon is

I always wonder if this will delete anything or is in fact the quit icon. I suggest to change it to something that's more typically used a quit icon, maybe this?

[waydabber]

Ohh, but this icon is already taken by the connect/disconnect dummy and I plan to use it for the hide display functionality as well.

I understand the problem, just don't see a good alternative. I think still a circled X is one of the better possibilities, as this resembles the close icon of macOS app windows.