pgsql: tests: Cope with io_method in TEMP_CONFIG in test_aio

tests: Cope with io_method in TEMP_CONFIG in test_aio

If io_method is set in TEMP_CONFIG the test added in 93bc3d75d8e fails,
because it assumes the io_method specified at initdb is actually used.

Fix that by appending the io_method again, after initdb (and thus after
TEMP_CONFIG has been added by Cluster.pm).

Per buildfarm animal bumblebee

Discussion: /messages/by-id/zh5u22wbpcyfw2ddl3lsvmsxf4yvsrvgxqwwmfjddc4c2khsgp@gfysyjsaelr5

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/327d987df1e72a9b146f312df0a5ed34ef148720

Modified Files
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src/test/modules/test_aio/t/001_aio.pl | 11 +++++++++++
1 file changed, 11 insertions(+)