Debug logging when saving a playlist.

src/playlist/playlistbackend.cpp

@@ -29,6 +29,7 @@
 
 #include "core/application.h"
 #include "core/database.h"
+#include "core/logging.h"
 #include "core/scopedtransaction.h"
 #include "core/song.h"
 #include "library/librarybackend.h"
@@ -287,6 +288,8 @@ void PlaylistBackend::SavePlaylist(int playlist, const PlaylistItemList& items,
   QMutexLocker l(db_->Mutex());
   QSqlDatabase db(db_->Connect());
 
+  qLog(Debug) << "Saving playlist" << playlist;
+
   QSqlQuery clear("DELETE FROM playlist_items WHERE playlist = :playlist", db);
   QSqlQuery insert(
       "INSERT INTO playlist_items"