Wizard: Strip user info from url

[TheOneRing]

If a user enters a URL with username or password encoded, we should remove that information and not send it to the server (QUrl::RemoveUserInfo)
The user info should just be ignored, and the wizard will behave as if no information was provided.

Originally posted by @TheOneRing in #11045 (comment)

[saw-jan]

Tested on ownCloud 6.0.0.13582-daily20240327 [4258b6]