* Correctly merge configurations that have client certificates set

  by SSLProxyMachineCertificate{File|Path}.
  The certificates and keys loaded during configuration time got lost during
  runtime if e.g. SSLProxyMachineCertificate{File|Path} was set on virtual host
  level and there was an SSL directive at directory level, e.g. SSLRequire.
  This fixes a regression likely introduced in r1740928.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1844002 13f79535-47bb-0310-9956-ffa450edef68