Swift proxy logs to syslog during the devstack-gate tempest runs. To
better capture the swift logs increase the rsyslog buffer size to 6k
bytes allowing for longer messages like tracebacks.
This was setup by openstack-infra previous during our diskimage
builds.
I03e42964e14d9f930c07ed047851bdf775639c59
Change-Id: Iaa232335865410600c93f47d4777ed4f1bce08e2
Signed-off-by: Paul Belanger <pabelanger@redhat.com>