pgsql: doc: Correct setting restrictions for vacuum_max_eager_freeze_fa

doc: Correct setting restrictions for vacuum_max_eager_freeze_failure_rate

The documentation incorrectly stated that this parameter could only
be set in postgresql.conf or on the server command line. However, it
is a PGC_USERSET parameter and can therefore be changed by any user
within a session.

Remove the incorrect restriction while retaining the note about the
per-table storage parameter override.

Backpatch to v18, where this parameter was introduced.

Author: Afrah Razzak <mypg(dot)afrah(at)gmail(dot)com>
Reviewed-by: Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
Discussion: https://postgr.es/m/CAAJ6gzGeup6WPpraF1g6iWYOQsvLmhKk94acJ=-iq+Gg_x9W0w@mail.gmail.com
Backpatch-through: 18

Branch
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REL_18_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/aae8f955723ae83c989cb558c7a439ab68dded8d

Modified Files
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doc/src/sgml/config.sgml | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)