Fix fs-pack-tests when run with --server-minor-version.
Fix fs-pack-tests when run with --server-minor-version.

* subversion/tests/libsvn_fs_fs/fs-pack-test.c
  (create_packed_filesystem): Preserve the the version number when
   rewriting the format file.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1089828 13f79535-47bb-0310-9956-ffa450edef68

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