packaging: setup: less strict parsing of pg_hba.conf

In addition to I374d578735c910451bc7698444a446728b33fd58,
also use a regexp for matching the 'engine' lines.

Change-Id: If43df5c1e22cd02a3ccd88acb36d35e1abbc6322
Signed-off-by: Yedidyah Bar David <didi@redhat.com>