Prevent Context.RemoteAddr() from exploding when called from ConnCallback
Prevent Context.RemoteAddr() from exploding when called from ConnCallback

When calling ctx.RemoteAddr() within ConnCallback one gets a panic due to
unsafe casting within the accessor. I understand it's not a valid scenario
as such, but I accidentally called a logger that expected that checked
for RemoteAddr() in ssh.Context

panic: interface conversion: interface is nil, not net.Addr

Signed-off-by: Alejandro Mery <cdfd70a51550235bbe9d06a3549b54fb5429c504@geeks.cl>

gliderlabs/ssh