Your site settings are in discourse database in the site_settings table:
discourse=# select count(1) from site_settings;
count
-------
78
(1 row)
This information is already includes in your DB backup and you could get it from there; or you could dump this table directly with this generic command line utility:
pg_dump -d <database_name> -t <table_name> > file.sql
for example:
su postgres -c 'pg_dump -d discourse -t site_settings > /shared/neo/my_site_settings.sql'
Actual example and results:
# su postgres -c 'pg_dump -d discourse -t site_settings > /shared/neo/my_site_settings.sql'
# cd /shared/neo
# ls -l
total 12
-rw-r--r-- 1 postgres postgres 10653 Apr 16 02:04 my_site_settings.sql
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