pgsql: doc: clarify "physical" replication slot creation on the primary

doc: clarify "physical" replication slot creation on the primary

Previously it was not clear that "physical" replication slots were being
discussed, and that they needed to be created on the primary and not the
standby.

Backpatch-through: master

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/a5b69e30731fb623715ecf4c8073c0f2dee41678

Modified Files
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doc/src/sgml/high-availability.sgml | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)