Followup to r1443578, hopefully fixing some segfaults triggered on
certain buildbots.

* subversion/libsvn_ra_serf/commit.c
  (checkout_node): Canonicalize the parsed Location header URI as a urlpath.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1443705 13f79535-47bb-0310-9956-ffa450edef68