Segfault fix.
Segfault fix.

* fetch.c (svn_ra_dav__get_file):  __get_one_prop may have returned
  error, so it's very possible the propval is still a default NULL!

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion