Merge r1733523, r1733691 from trunk:

Use ap_array_str_contains to simplify code

Use ap_array_str_contains to simplify code
Remove a useless test (groups is always NULL)
Improve some style

Submitted by: jailletc36
Reviewed by: jailletc36, jim, ylavic
Backported by: ylavic


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1734395 13f79535-47bb-0310-9956-ffa450edef68