Before, when city_id was not set, both city and city_id
were shown, so when you created a new partner, you would
see 2 city fields in a weird way.
Now, we only show both fields when city is set, but not city_id
That way, in case you have some old partners before the installation
of the module, it will still work.
opw-2178992
closesodoo/odoo#43871
X-original-commit: 0a2cf833f9935c44d09ff7c46513dbc37c57bfe8
Signed-off-by: Josse Colpaert <jco@openerp.com>