Remove false protocol limit checks from the ra_svn marshaller.

* subversion/libsvn_ra_svn/marshal.c
  (svn_ra_svn__read_data_log_changed_entry): Remove upper limit
   check for variable length elements as they may be extended by
   later releases.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1561570 13f79535-47bb-0310-9956-ffa450edef68