On the fsfs-format7 branch: Fix test_repos_info test for FSX

* subversion/tests/libsvn_repos/repos-test.c
  (test_repos_info): don't attempt to create a FSX in a pre-1.9
                     compatible way

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsfs-format7@1507729 13f79535-47bb-0310-9956-ffa450edef68