Thanks goes to Manoj, while commenting on another issue, for triggering

  Thanks goes to Manoj, while commenting on another issue, for triggering
  this idea.  If we find files matching (e.g. index.html.bak matches
  index.html) but they are rejected because we don't understand them
  (e.g. they are a directory, or .bak isn't a mod_mime recognized extension)
  then Error 500 out of here, with a note for the system administrator
  explaining that index.html matches some files, but their extensions
  cannot be grokked.  No more (unintentional, or situational) autoindex :)

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@89961 13f79535-47bb-0310-9956-ffa450edef68