Fix handling of ProxyBlock if a forward proxy is configured, and fix

Fix handling of ProxyBlock if a forward proxy is configured, and fix
mod_proxy_connect to avoid an inappropriate DNS lookup:

* modules/proxy/proxy_util.c (ap_proxy_checkproxyblock): Take hostname
  argument, make address argument optional.  Check names against
  hostname arg, omit if addr not given.
  (ap_proxy_determine_connection): Adjust for the above; pass hostname
  from URI not the next hop.

* modules/proxy/mod_proxy_ftp.c (proxy_ftp_handler): Adjust for
  ap_proxy_checkproxyblock change.

* modules/proxy/mod_proxy_connect.c (proxy_connect_handler): Adjust
  similarly, and avoid the DNS lookup on the request-URI hostname if a
  proxy is used.

* include/ap_mmn.h: Bump MMN.

PR: 43697

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1365001 13f79535-47bb-0310-9956-ffa450edef68