pgsql: Fix custom validators call in build_local_reloptions()

Fix custom validators call in build_local_reloptions()

We need to call them only when validate == true.

Backpatch to 13, where opclass options were introduced.

Reported-by: Tom Lane
Discussion: https://postgr.es/m/2656633.1681831542%40sss.pgh.pa.us
Reviewed-by: Tom Lane, Pavel Borisov
Backpatch-through: 13

Branch
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REL_13_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/02191136cb25670dc9f086248f7b495d68c965d5

Modified Files
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src/backend/access/common/reloptions.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)