use unbuffered i/o for script adding launchpad comments
use unbuffered i/o for script adding launchpad comments

Using unbuffered I/O should let us see some output sooner and make
debugging hangs easier.

Change-Id: I26d2f207fa7d4083cefc5521b113f57a45f8a53e
Signed-off-by: Doug Hellmann <0798ebecfb7bc4dfb9d0445c2fa030eb64e1fa1c@doughellmann.com>

openstack-infra/project-config,openstack-infra/project-config