mpdpp: make it possible to send playlist_delete command in commands list

this fixes #3749

src/mpdpp.cpp

@@ -714,10 +714,14 @@ void Connection::Delete(unsigned pos)
 
 void Connection::PlaylistDelete(const std::string &playlist, unsigned pos)
 {
-	prechecksNoCommandsList();
+	prechecks();
-	mpd_run_playlist_delete(m_connection, playlist.c_str(), pos);
+	mpd_send_playlist_delete(m_connection, playlist.c_str(), pos);
+	if (!m_command_list_active)
+	{
+		mpd_response_finish(m_connection);
 		checkErrors();
 	}
+}
 
 void Connection::StartCommandsList()
 {