Add a regression test for issue #4490 'svnrdump load crashes on a prop
change in a non-deltas dump'.

* subversion/tests/cmdline/svnrdump_tests.py
  (load_prop_change_in_non_deltas_dump): New test.
  (test_list): Run it.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1586668 13f79535-47bb-0310-9956-ffa450edef68