Complete the lbmethods patch in the case of --enable-proxy-balancer=shared

(that value was forgotten once the module was enabled), and note a nice-to-have
backport that isn't critical for 2.4.23.



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1750554 13f79535-47bb-0310-9956-ffa450edef68