QUIT does not respect server-time

[slingamn]

e.g. :c!~u@tcrp2947vxqnw.irc QUIT :Ping timeout: 2m30s

ergo/irc/client.go

Lines 1193 to 1197 in 7e18362

	// #364: don't send QUIT lines to unregistered clients
	if client.registered {
	quitMsg := ircmsg.MakeMessage(nil, client.nickMaskString, "QUIT", message)
	finalData, _ = quitMsg.LineBytesStrict(false, MaxLineLen)
	}

Right now we send the same QUIT line to all sessions regardless of their caps. This should respect the server-time cap.