check the return value of ap_run_pre_connection(). So if the

pre_connection phase fails (without setting c->aborted)
ap_run_process_connection is not executed.
PR:
Obtained from:
Submitted by:
Reviewed by:	trawick, jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@98798 13f79535-47bb-0310-9956-ffa450edef68