This patch adds `%P` to the SIP log4perl configuration so that PID is
recorded against log lines.
This allows transactions to be more easily tied together under one
SIPServer, thus making it easier to pick out a whole transaction from
start to finish.
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
