modules/ssl/ssl_util_ocsp.c (get_line): Don't set line[-1] to 0

when len == 0.

Backport of r1358061 from trunk.

Submitted by: Jim Meyering <meyering redhat.com>
Reviewed by: jorton, trawick, rjung
Backported by: rjung


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1364270 13f79535-47bb-0310-9956-ffa450edef68