Fix segfault with logresolve -c and IPv6

Due to a logic error, there could be a NULL pointer dereference.

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=823259


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1745863 13f79535-47bb-0310-9956-ffa450edef68