Fix bogus size in ap_snprintf call that I introduced in 1.2b<mumble>.

Is a bigger problem now because of the ap_snprintf changes to treat
len of 0 == 0 instead of infinite.

PR:
Obtained from:
Submitted by:
Reviewed by:	Jim Jagielski, Dean Gaudet


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@79807 13f79535-47bb-0310-9956-ffa450edef68