Record the fact that we failed to set the username as requested.

This is useful to know as the most likely cause will be a misconfiguration
and so should be easily fixed, but to be fixed it's helpful if you're
aware it needs fixed!



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@279893 13f79535-47bb-0310-9956-ffa450edef68