Base formspec coordinate size on padded screensize

src/gui/guiFormSpecMenu.cpp

@@ -3265,7 +3265,7 @@ void GUIFormSpecMenu::regenerateGui(v2u32 screensize)
 						((15.0 / 13.0) * (0.85 + mydata.invsize.Y));
 			}
 
-			s32 min_screen_dim = std::min(mydata.screensize.X, mydata.screensize.Y);
+			s32 min_screen_dim = std::min(padded_screensize.X, padded_screensize.Y);
 
 #ifdef HAVE_TOUCHSCREENGUI
 			// In Android, the preferred imgsize should be larger to accommodate the