Credentials can't be changed after initial login

[skjiisa]

If I create a WebDAVFileProvider with given credentials, I can't later create a new one with different credentials until the app is restarted. If I use the same username and host as the first Provider, I can use any password I want and it will authenticate properly, implying it cached the original password. If I use a different username and host, then I cannot login with a new WebDAVFileProvider.