Use DBus interface to pause clementine

The --pause option does not work in all versions:

    https://bugzilla.redhat.com/show_bug.cgi?id=1348678

dotfiles/config/bmo/hook.ini

     say_zleeping = weechat-fifo -s \*/disconnect -all offline
 
     afk          = pidof mocp       && mocp --pause
-    afk          = pidof clementine && clementine --pause
+    afk          = pidof clementine && qdbus org.mpris.clementine /Player org.freedesktop.MediaPlayer.Pause
 
     back         = bmo nag -R