Change prototype of vm_construct, to work around gcc bug which

causes a segfault.

PR: 52779
Submitted by: Dick Snippe <Dick Snippe tech omroep nl>


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1351012 13f79535-47bb-0310-9956-ffa450edef68