add a bit of error checking to the mod_cgid daemon's logic to read

the request over the unix socket

it isn't perfect (EINTR, partial reads) but it is good enough to
avoid segfaulting if some code tries to verify that cgid is active
by connecting to its unix socket


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@93790 13f79535-47bb-0310-9956-ffa450edef68