when asking the providers for authentication, the main loop should

when asking the providers for authentication, the main loop should
not only  break, if access is granted. It should also break, if
access was *denied*  by one provider. To be safe, it has to break
also, if an error occured. So  the patch turns the condition around
and continues only, if the user was  not found.
I find it also weird, that if auth was denied (by password
usually), the  AuthBasicAuthoritative behaviour can override that
by "passing to lower  modules". The patch changes that behaviour,
too.

Justin notes:
I'm kind of on the fence about that.  I was originally thinking
optimistically, but yeah, it might make sense to do it
pessimistically.  If there's any error, bug out.

Submitted by:	Andre Malo <nd@perlig.de>

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@97801 13f79535-47bb-0310-9956-ffa450edef68