Bugfix: Avoid Game to crash (stack overflow) when an error occurs and we have an active MOUSE_REGION

git-svn-id: https://ja2svn.mooo.com/source/ja2/trunk/GameSource/ja2_v1.13/Build@2468 3b4a5df2-a311-0410-b5c6-a8a6f20db521

Standard Gaming Platform/mousesystem.cpp

@@ -566,6 +566,12 @@ void MSYS_UpdateMouseRegion(void)
 	BOOLEAN fFound=FALSE;
 	found=FALSE;
 
+	// WANNE: Error handling Bugfix by birdflu (to avoid Stack Overflow)
+	if(guiCurrentScreen == ERROR_SCREEN)
+	{
+		return;
+	}
+
 	// Check previous region!
 	if(MSYS_Mouse_Grabbed)
 	{