Fix typo in configure script when checking for mod_so. bash

doesn't seem to have a problem but /bin/sh on Solaris does.
Symptom: "./configure: test: unknown operator =="


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@85434 13f79535-47bb-0310-9956-ffa450edef68