proxy_util: Schemes and hostnames that are "too long" are

no longer automatically fatal errors but are instead logged
and truncated, at which point the admin can determine if that
is OK or not.
trunk patch: http://svn.apache.org/r1823482
+1: jim, minfrin, rpluem


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1824455 13f79535-47bb-0310-9956-ffa450edef68