ra_serf: Don't fetch properties for added directories in send-all mode.

* subversion/libsvn_ra_serf/update.c
  (start_report): Set add_props_included to TRUE in send-all mode.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1436236 13f79535-47bb-0310-9956-ffa450edef68