Updates border_nor in the config environment. Call this at the start of
a script to change the default border argument of
nor_locations_names(), nor_locations_redistricting(),
nor_locations_hierarchy_from_to(), nor_population_by_age_cats() and
nor_population_by_sex_age_cats().
Value
Invisibly, the value assigned to config$border_nor, or NULL
when border_nor is NULL. The function exists for its side effect on
config.
