Disabling nmcheck.gnome connectivity checker in Ubuntu 17.10

Got ratty with the automated connectivity check / captive portal 'helper' today whilst bouncing my internet.

Found some instructions at fedoraforum.org (which themselves link to blogs.gnome.org ...

Key fix applied: modify "/etc/NetworkManager/NetworkManager.conf" and add this at the bottom:

[connectivity]
uri=
interval=0

I trust that I won't see it again. :|