Follow-up to r27259, stop using unsupported -g option in merge_tests.py.
Follow-up to r27259, stop using unsupported -g option in merge_tests.py.

* subversion/tests/cmdline/merge_tests.py
  (mergeinfo_inheritance_and_discontinuous_ranges,
  detect_copy_src_for_target_with_multiple_ancestors,
  merge_with_auto_rev_range_detection,
  mergeinfo_recording_in_skipped_merge,
  propchange_of_subdir_raises_conflict,
  merge_target_with_non_inheritable_mergeinfo): No more
  -g/--use-merge-history.

git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@867339 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion