Song Change Notifications do not work in Flatpak version

[BaronKrause]

Tested on 2 different 20.04 Pop_OS Machines using the Flatpak version, the song change notifications when enabled in the plugins do not seem to work.

I tested with and without enabling the "Notification Icon" plugin and making sure its closed/minimized to the system tray before the song change.

[TingPing]

I can reproduce it not working.

[rcalixte]

@BaronKrause Would you be interested in testing #680? This PR aims to address the issue but I can only vouch for the environments I've tested on (or would be willing to install myself). If you can test with at least one of your Pop!_OS machines, I can generate a flatpak ref or you can build and install locally using flatpak-builder based on the branch of the forked repository.

[zdc26z]

@rcalixte If this is still needs testing, I am having the same issue on EndeavourOS using i3wm with dunst for notifications, and I am willing to test.

[rcalixte]

@zdc26z The fix is still a work in progress. When we're ready, we can ping you for testing. Thank you!