Merge r1476680 from trunk:

mod_proxy: Clarify the usage suggestion for BalancerInherit and ProxyPassInherit.

Submitted by: minfrin
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1477650 13f79535-47bb-0310-9956-ffa450edef68