clean up the invocation of APR_CHECK_APR_DEFINE()...

it no longer references the second parameter, which was
incorrectly specified with out-of-tree APR anyway
(which resulted in prefork being selected on Unix since
we didn't ever think APR had thread support)


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@98917 13f79535-47bb-0310-9956-ffa450edef68