mpris: send correct desktop-entry hints
mpris: send correct desktop-entry hints

According to spec [1], the ".desktop" suffix must not be present.

[1]: https://developer.gnome.org/notification-spec/

grawity/hacks,grawity/hacks,grawity/hacks,grawity/hacks,grawity/hacks,grawity/hacks,grawity/hacks