Duplicate Widgets

[AncientGrief]

I created a theme with a widget for the desktop and mobile menu (responsive @ media CSS).
Inside the admin panel they're duplicated (same ZoneName).

Adding a widget to WidgetZone1 will affect both (as expected)...

To fix this, maybe add this line to WidgetsVM.cs:
if (WidgetZones.Exists(x => x.Id == zone.Id)) continue;
right after foreach (XmlNode node in widgets.ChildNodes)

I would create a pull request, but my forked repo is 4 commits ahead and I donno how to create a PR for a single commit ...