On the fsfs-format7 branch.

* subversion/libsvn_fs_fs/pack.c
  (write_changes_containers): fix test for non-empty APR arrays


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsfs-format7@1481445 13f79535-47bb-0310-9956-ffa450edef68