pgsql: doc: clarify the behavior of unopenable listen_addresses

doc: clarify the behavior of unopenable listen_addresses

Reported-by: Gurjeet Singh

Discussion: /messages/by-id/CABwTF4WYPD9ov-kcSq1+J+ZJ5wYDQLXquY6Lu2cvb-Y7pTpSGA@mail.gmail.com

Backpatch-through: 11

Branch
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REL_12_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/95b6b230a730d29fdb2f7f634da1afbb1f0c280f

Modified Files
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doc/src/sgml/config.sgml | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)