Improve access logging output to use information based on source address instead of a peer address for Remote host (%h) and Remote IP (%a).

A remote host and ip address information are transferred through AJP protocol when a request is forwarded via a front-end proxy using AJP (like Apache httpd mod_proxy/mod_jk/mod_cluster). However, undertow's access logging always output a peer address information for Remote host (%h) and Remote IP (%a) even if it's forwarded via a front-end proxy using AJP protocol.