ensure that ap_rgetline allocates storage for the request line each time it is

called.

This fixes a number of segfaults on daedalus where the first line is
empty (i.e. \r\n followed by a bunch of garbage)


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@93332 13f79535-47bb-0310-9956-ffa450edef68