Cancel boxmenu if not clicking tab

contextmenu is set causing it to open for anywhere in the box area
that's white
only show if right clicking the tab at the top

PKHeX.WinForms/Controls/SAV Editor/SAVEditor.cs

@@ -93,6 +93,7 @@ public SAVEditor()
             GB_Daycare.Click += SwitchDaycare;
             FLP_SAVtools.Scroll += WinFormsUtil.PanelScroll;
             Tab_Box.ContextMenuStrip = SortMenu = new BoxMenuStrip(this);
+            SortMenu.Opening += (s, x) => x.Cancel = !tabBoxMulti.GetTabRect(tabBoxMulti.SelectedIndex).Contains(PointToClient(MousePosition));
 
             M.OtherSlots.Add(this);
             SL_Extra.ViewIndex = -2;