pgsql: Further tweak the default behavior of psql's \dconfig.

Further tweak the default behavior of psql's \dconfig.

Define "parameters with non-default settings" as being those that
not only have pg_settings.source different from 'default', but
also have a current value different from the hard-wired boot_val.
Adding the latter restriction removes a number of not-very-interesting
cases where the active setting is chosen by initdb but in practice
tends to be the same all the time.

Per discussion with Jonathan Katz.

Discussion: https://postgr.es/m/YlFQLzlPi4QD0wSi@msg.df7cb.de

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/139d46ee26a2c7813d02739d35fa305890643ac1

Modified Files
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src/bin/psql/describe.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)