David Crawshaw 293a2b11cd ipn: allow b to be nil in NewBackendServer
A couple of code paths in ipnserver use a NewBackendServer with a nil
backend just to call the callback with an encapsulated error message.
This covers a panic case seen in logs.

For #1920

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
2021-05-19 09:33:19 -07:00
..
2020-12-30 17:33:02 -08:00