HPCC-8664 - Addition tracing for MP MultiPacket error

log details of the multi header that's already being received.

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>
Merge pull request #3897 from jakesmith/hpcc-8664

HPCC-8664 - Addition tracing for MP MultiPacket error

Reviewed-By: Gavin Halliday <gavin.halliday@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>