Show profile is expired

When the profile is expired, the validity displayed to the user is confusing.

> Your account is valid for
> **-7 more minutes**

[WpfApp/Menu/InstalledProfile.xaml.cs](https://github.com/geteduroam/windows-app/blob/geteduroam-3.2.5/WpfApp/Menu/InstalledProfile.xaml.cs#L48-L78)

The UI should just show that the credential is expired, and possibly have a button to renew the credential.