When dbus restarts it can cause the tailscaled to crash because the nil
signal was not handled in resolved.Fixing so the nil signal leads to a
connection reset and tailscaled stays connected to systemd when dbus restarted.
Fixes#4645
Co-authored-by: James Tucker <james@tailscale.com>
Signed-off-by: nyghtowl <warrick@tailscale.com>
Co-authored-by: James Tucker <james@tailscale.com>
