Glitch in the Custom category of the presets view

Steps to reproduce:

1. Save a custom preset (unless you already have custom presets)
2. Switch to the Custom tab
3. Select a Custom preset and save it as another preset.

Result:

The underlying blue bar (under the word "Custom" in the view's header) disappears. This happens after / because of a reset of the category model (`m_categoryModel->reset();` in 

`QdsNewDialog::savePresetDialogAccept()`). In NewProjectDialog.qml this happens in the "strip" item when the properties "x" and "width" are computed - they will both have the value 0.

NOTE:

I tried using onComplete in the Text item of the "repeater" item, but it looks like even at the point where onComplete is called for the Custom text item, the x and width properties are still 0.