Try to fix a test failure on the unix buildbots.

* subversion/tests/cmdline/svntest/main.py
  (create_repos): Don't install a passed fsfs.conf file for repository formats
    that don't have an fsfs.conf as this file would be unused and hotcopy tests
    will fail.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1561703 13f79535-47bb-0310-9956-ffa450edef68