pgsql: Fix test failure in 021_twophase.pl.

Fix test failure in 021_twophase.pl.

The test is expecting two prepared transactions corresponding to two
subscriptions but it waits to catch up for just one subscription. Fix it
by allowing to wait for both subscriptions.

Reported-by: Michael Paquier, as per buildfarm
Author: Ajin Cherian
Reviewed-By: Amit Kapila, Vignesh C, Peter Smith
Discussion: https://postgr.es/m/CAA4eK1+_0iNQ8Z=KVTjmmAqNX-hyv+1+fnZ-Yx8CVP=uAcekqw@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/eaf5321c352478266cebe2aa50ea4c34a8fdd2c7

Modified Files
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src/test/subscription/t/021_twophase.pl | 2 ++
1 file changed, 2 insertions(+)