In svnsync: disable some ev2 test code when not using the ev2 shims.

* subversion/svnsync/svnsync.c
  (replay_baton_t): Hide unused value.
  (fetch_base_func,
   fetch_props_func,
   fetch_kind_func,
   get_shim_callbacks): Hide using preprocessor when not needed.
  (replay_rev_started): Don't initialize ev2 shims.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1553369 13f79535-47bb-0310-9956-ffa450edef68