Use svn_hash_gets() for an apr_hash containing a single item, instead of a
hash iterator.

* subversion/libsvn_client/add.c
  (svn_client__get_all_auto_props): Use hash fetch. Leave whitespace change
    for separate commit.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1482939 13f79535-47bb-0310-9956-ffa450edef68