[mod_auth] require digest uri= match original URI

[mod_auth] require digest uri= match original URI

lighttpd requires a strict match between the request URI and the uri=
auth-param provided in the Authenticate header.  lighttpd does not
attempt to determine if different URIs are semantically equivalent.

This commit removes a condition which permitted an Authenticate header
with a uri= containing a query-string to be used with the request-uri
which did not contain any query-string.  The condition was likely added
in the original implementation which operated on lighttpd request.uri
instead of the correct request.orig_uri (original URI sent to lighttpd).

.

HTTP Digest Access Authentication
https://www.rfc-editor.org/rfc/rfc7616.txt

3.4.6.  Various Considerations

   The authenticating server MUST assure that the resource designated by
   the "uri" parameter is the same as the resource specified in the
   Request-Line; if they are not, the server SHOULD return a 400 Bad
   Request error.  (Since this may be a symptom of an attack, server
   implementers may want to consider logging such errors.)  The purpose
   of duplicating information from the request URL in this field is to
   deal with the possibility that an intermediate proxy may alter the
   client's Request-Line.  This altered (but presumably semantically
   equivalent) request would not result in the same digest as that
   calculated by the client.

x-ref:
  "HTTP Digest Access Authentication"
  https://www.rfc-editor.org/rfc/rfc7616.txt
  "HTTP digest authentication not compatible with some clients"
  https://redmine.lighttpd.net/issues/2974