[BUG]: Problems with minimizing /w tray icon

[kyrawertho]

Brief description of the issue.

Application opens and immediately closes when opened from systray, but stays active on opening for the second time.

How to reproduce the bug?

1. Using options Hide main window when minimized & Tray icon
2. Minimize application to tray
3. Click on systray icon to open – application comes up and disappears again
4. Click icon again for window to stay active

I've finally noticed this doesn't happen when I close with [ X ], only when using minimize [ _ ].

What was the expected result?

Minimize to tray should work the same as close to tray.

Other information

Operating System: KDE neon 5.21
KDE Plasma Version: 5.21.1
KDE Frameworks Version: 5.79.0
Qt Version: 5.15.2
Kernel Version: 5.4.0-66-generic

RSS Guard version: 3.9.0*
(another note: "rssguard --version" simply shows "rssguard", no version number)

[martinrotter]

Managed to reproduce the problem. It seems to happen only on KDE, Windows works fine.

[martinrotter]

OK, I fixed it. Fix will appear in 4.x major milestone release and was also backported to 3.9.1 which will come when more fixes arrive to it.