Tweak new merge test to make it run properly on Windows.

* subversion/tests/cmdline/merge_tests.py
  (merge_conflict_when_keywords_removed): Don't use hard-coded path
   separators.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1430561 13f79535-47bb-0310-9956-ffa450edef68