Avoid potential core dump. This patch is a small part of a larger

patch for the ap_unparse_uri_components() routine, and can be safely
applied independently.
Submitted by:	"Jeffrey W. Baker" <jwbaker@acm.org>
Reviewed by:	Jim Jagielski, Martin Kraemer


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@88209 13f79535-47bb-0310-9956-ffa450edef68