When a username and password are provided in the URL, they were wrongly
removed from the stored URL so that subsequent uses of the same URL
wouldn't find the crendentials. This made doing HTTP auth with multiple
connections (like Digest) mishave.
Regression from 46e164069d (7.62.0)
Test case 335 added to verify.
Reported-by: Mike Crowe
Fixes#4228Closes#4229
