When we press the keyboard shortcuts to change the volume, notification says "pa-applet" instead of the volume.
It's the same problem as here:
https://github.com/fernandotcl/pa-applet/issues/16
And, an unnecessary 'pa-applet' notification icon remains in the tray instead of disappearing on its own. By the way, this tray icon shouldn't have appeared at all in this situation.
