These ignore built files that don't exist anymore, and just serve
to clutter up the .gitignore file. (I was initially confused when
I saw those lines, since I (correctly) thought that the only
Tailscale binaries were tailscale and tailscaled):
- taillogin was removed in d052586
- relaynode was removed in a56e853
Signed-off-by: Smitty <me@smitop.com>
