pgsql: Make new SSL TAP test for channel_binding more robust

Make new SSL TAP test for channel_binding more robust

The test would fail in an environment including a certificate file in
~/.postgresql/. bdd6e9b fixed a similar failure, and d6e612f introduced
the same problem again with a new test.

Author: Kyotaro Horiguchi
Discussion: /messages/by-id/20200804.120033.31225582282178001.horikyota.ntt@gmail.com
Backpatch-through: 13

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/dd877998d498c511352bd3640fd57f041c90ea62

Modified Files
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src/test/ssl/t/002_scram.pl | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)