fix app window flashing on osx
fix app window flashing on osx

caused by refocusing when calling app.dock.show()
multiple times
bseber/yakyak,averissimo/yakyak,arnriu/yakyak,yakyak/yakyak,yakyak/yakyak,refack/yakyak,monchote/yakyak,monchote/yakyak,refack/yakyak,bseber/yakyak,bseber/yakyak,averissimo/yakyak,yakyak/yakyak,refack/yakyak,monchote/yakyak,arnriu/yakyak,averissimo/yakyak,arnriu/yakyak