multimedia/mpv-mpris: update to 1.0

Changelog:

 * rename album fields to match MusicBrainz internal names by @tpeacock19 in #81
 * Fix string leaks in property change handler by @mia-0 in #84
 * Makefile: Allow to append CFLAGS / LDFLAGS from environment. by @olifre in #87
 * Do not use the default GMainContext by @gnome-mpv in #88