merge this fix from 2.1-dev:

*) ab: Work over non-loopback on Unix again. PR 21495.

The CHANGES entry is currently under the 2.0.48 heading.  We
can figure out what to change once 2.0.48 is out the door.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/APACHE_2_0_BRANCH@101241 13f79535-47bb-0310-9956-ffa450edef68