fix debug questmap command (#5206)

Source/debug.cpp

@@ -238,6 +238,11 @@ std::string DebugCmdLoadQuestMap(const string_view parameter)
 		if (!MyPlayer->isOnLevel(quest._qlevel)) {
 			StartNewLvl(*MyPlayer, (quest._qlevel != 21) ? interface_mode::WM_DIABNEXTLVL : interface_mode::WM_DIABTOWNWARP, quest._qlevel);
 			ProcessMessages();
+			// Workaround for SDL_PollEvent:
+			// StartNewLvl pushes a new event with SDL_PushEvent.
+			// ProcessMessages calls SDL_PollEvent but SDL ignores the new pushed event.
+			// Calling SDL_PollEvent again fixes this.
+			ProcessMessages();
 		}
 
 		setlvltype = quest._qlvltype;