doc: Document that only superusers can use pg_import_system_collations().
Back-patch to v10 where pg_import_system_collations() was added.
Author: Atsushi Torikoshi
Discussion:
@@ -21687,6 +21687,7 @@ postgres=# SELECT * FROM pg_walfile_name_offset(pg_stop_backup());
be <literal>pg_catalog</literal>, but that is not a requirement;
the collations could be installed into some other schema as well.
The function returns the number of new collation objects it created.
+ Use of this function is restricted to superusers.
</para>
<table id="functions-info-partition">
