pgpool: Test: fix occasional failure of 034.promote_node.

Test: fix occasional failure of 034.promote_node.

The error is caused by follow primary process. In the process
pg_rewind is executed to sync a standby with new primary. If new
primary promotion is slow, pg_rewind incorrectly returns "there's no
need to pg_rewind". Even if new standby starts, the standby causes an
error later on which make the 034.promote_node test failed.

To fix this, add CHECKPOINT in the failover script. Also add "-c"
option pg_rewind to retrieve WAL from archives so that pg_rewind could
find necessary WAL.

Reported-by: Bo Peng <pengbo(at)sraoss(dot)co(dot)jp>
Suggested-by: Bo Peng <pengbo(at)sraoss(dot)co(dot)jp>
Backpatch-through: v4.3

Branch
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V4_3_STABLE

Details
-------
https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=55eb137c13a737ae7b250246b4292d8778fe2d56

Modified Files
--------------
src/test/pgpool_setup.in | 27 +++++++++++++++++++++++++--
1 file changed, 25 insertions(+), 2 deletions(-)