Commit when adding track to header

Fixes #238

app/playlistmodel.py

@@ -185,6 +185,7 @@ class PlaylistModel(QAbstractTableModel):
                 self.refresh_row(session, row_number)
                 # Repaint row
                 self.invalidate_row(row_number)
+                session.commit()
 
         self.signals.resize_rows_signal.emit(self.playlist_id)
 
@@ -1123,6 +1124,7 @@ class PlaylistModel(QAbstractTableModel):
                 self.refresh_row(session, row_number)
                 self.invalidate_row(row_number)
                 self.signals.resize_rows_signal.emit(self.playlist_id)
+                session.commit()
 
     def reset_track_sequence_row_numbers(self) -> None:
         """