Undo extra chattiness of postmaster logs in TAP tests.
Undo extra chattiness of postmaster logs in TAP tests.

Commit 6271fceb8 changed PostgresNode.pm to force log_min_messages = debug1
in all TAP tests, without any discussion and without a concrete need for
it.  This makes some of the TAP tests noticeably slower (although much of
that may be due to poorly-written regexes), and for certain it's bloating
the buildfarm logs.  Revert the change.

Discussion: ec147df8dfc228f3387c90ad848150eb04d2215d@sss.pgh.pa.us

greenplum-db/gpdb,xinzweb/gpdb,greenplum-db/gpdb,50wu/gpdb,xinzweb/gpdb,greenplum-db/gpdb,adam8157/gpdb,greenplum-db/gpdb,lisakowen/gpdb,xinzweb/gpdb,lisakowen/gpdb,50wu/gpdb,lisakowen/gpdb,adam8157/gpdb,50wu/gpdb,greenplum-db/gpdb,adam8157/gpdb,adam8157/gpdb,xinzweb/gpdb,50wu/gpdb,adam8157/gpdb,xinzweb/gpdb,adam8157/gpdb,adam8157/gpdb,50wu/gpdb,greenplum-db/gpdb,xinzweb/gpdb,greenplum-db/gpdb,50wu/gpdb,adam8157/gpdb,lisakowen/gpdb,lisakowen/gpdb,50wu/gpdb,lisakowen/gpdb,lisakowen/gpdb,50wu/gpdb,xinzweb/gpdb,greenplum-db/gpdb,lisakowen/gpdb,xinzweb/gpdb