pgsql: Fix format truncation issue from ECPG test

Fix format truncation issue from ECPG test

This fixes one warning generated by GCC and present in the test case
array part of ECPG.  This likely got missed in past fixes like 3a4b891
because the compilation of those tests is not done by default.

Reported-by: Sergei Kornilov
Discussion: https://postgr.es/m/14951331562847675@sas2-a1efad875d04.qloud-c.yandex.net

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/a9f301df0e76c38d4544477c1b3e5e29d57904e6

Modified Files
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src/interfaces/ecpg/test/expected/sql-array.c | 2 +-
src/interfaces/ecpg/test/sql/array.pgc        | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)