Add a setting for automatically set min sizing values.

src/gfx.cpp

@@ -1165,6 +1165,8 @@ void ScreenSizeChanged()
 
 	/* screen size changed and the old bitmap is invalid now, so we don't want to undraw it */
 	_cursor.visible = false;
+
+	CheckWindowMinSizings();
 }
 
 void UndrawMouseCursor()