ra_serf: Fix pool lifetime bug with the checksum attribute.
ra_serf: Fix pool lifetime bug with the checksum attribute.

(Fixes svnsync tests #1-4.)

* subversion/libsvn_ra_serf/replay.c
  (start_replay): Copy the checksum to a pool that'll live long enough.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion