mpvpart: load subtitles on play

Signed-off-by: Mavridis Philippe <mavridisf@gmail.com>

kaffeine/src/player-parts/libmpv-part/libmpv_part.cpp

@@ -415,6 +415,7 @@ void MpvPart::slotPlay() {
         emit signalRequestCurrentTrack();
     }
 
+    slotReloadSubtitles();
     stateChanged(isStream() ? "playing_stream" : "playing_file");
 }