[systemd] Use snapcast service for snap

systemd/.config/systemd/user/snapclient.service

@@ -2,7 +2,7 @@
 Description=Snapclient
 
 [Service]
-ExecStart=/usr/bin/snapclient -h mopidy2.local
+ExecStart=/usr/bin/snapclient -h snapcast.service
 ExecStop=kill $(pidof snapclient)
 Restart=on-failure