Thread: pgsql: Adjust regex for test with opening parenthesis in character clas

Adjust regex for test with opening parenthesis in character classes

As written, the test was throwing an error because of an unbalanced
parenthesis.  The regex used in the test is adjusted to not fail and to
test the case of an opening parenthesis in a character class after some
nested square brackets.

Oversight in d46911e584d4.

Discussion: https://postgr.es/m/16ab039d1af455652bdf4173402ddda145f2c73b.camel@cybertec.at

Branch
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REL_13_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/31ee5ec698ed04c8ffd7e804b9d671bf31cb1ae4

Modified Files
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src/test/regress/expected/strings.out | 9 +++++++--
src/test/regress/sql/strings.sql      | 2 +-
2 files changed, 8 insertions(+), 3 deletions(-)