Fix a minor consistency issue when creating pre-1.5 repositories.

Since we didn't have config files back then, we don't hotcopy them.
Thus, we should not even create it in the first place.

* subversion/libsvn_fs_fs/fs_fs.c
  (svn_fs_fs__create): Only create fsfs config files when all
                       servers reading that repo would actually
                       use the that file.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1547454 13f79535-47bb-0310-9956-ffa450edef68