pgsql: doc: Fix link to SELinux user guide in sepgsql page

doc: Fix link to SELinux user guide in sepgsql page

Reported-by: Anton Voloshin
Discussion: /messages/by-id/15a86d4e-a237-1acd-18a2-fd69730f1ab9@postgrespro.ru
Backpatch-through: 10

Branch
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REL_11_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/c7ddbc351d9cff4f8a63155f6f1a524b41f6f23c

Modified Files
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doc/src/sgml/sepgsql.sgml | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)