Trivial reproducer:

Dim Dlg As Object
DialogLibraries.LoadLibrary("Standard")
Dlg = CreateUnoDialog(DialogLibraries.Standard.Dialog1)
Dlg.Execute()
Dlg.dispose()

Regression from 6c61b20a.

Change-Id: Ia62778c6d94f54e6097a307701e5c81be847665d
Reviewed-on: https://gerrit.libreoffice.org/4023Reviewed-by: Miklos Vajna <vmiklos@suse.cz>
Tested-by: Miklos Vajna <vmiklos@suse.cz>