openshift.ks: Fix httpd auth conf permissions

Bug 1079166
https://bugzilla.redhat.com/show_bug.cgi?id=1079166

`cp` invocation didn't preserve permissions from source file

Collapsed `configure_remote_user_auth_plugin` into
`configure_httpd_auth` function
Merge pull request #327 from dobbymoodge/BZ1079166

openshift.ks: Fix httpd auth conf permissions