pass the require-sasl message through from the script

irc/client.go

 	cloakedHostname    string
 	realname           string
 	realIP             net.IP
+	requireSASLMessage string
 	requireSASL        bool
 	registered         bool
 	registrationTimer  *time.Timer
 		proxiedIP:      proxiedIP,
 		requireSASL:    requireSASL,
 	}
+	if requireSASL {
+		client.requireSASLMessage = banMsg
+	}
 	client.writerSemaphore.Initialize(1)
 	client.history.Initialize(config.History.ClientLength, time.Duration(config.History.AutoresizeWindow))
 	client.brbTimer.Initialize(client)

irc/gateways.go

 		return errBanned, banMsg
 	}
 	client.requireSASL = requireSASL
+	if requireSASL {
+		client.requireSASLMessage = banMsg
+	}
 	// successfully added a limiter entry for the proxied IP;
 	// remove the entry for the real IP if applicable (#197)
 	client.server.connectionLimiter.RemoveClient(session.realIP)

irc/server.go

 			return true, false, output.BanMessage
 		} else if output.Result == IPRequireSASL {
 			server.logger.Info("connect-ip", "Requiring SASL from client due to ip-check-script", ipaddr.String())
-			return false, true, ""
+			return false, true, output.BanMessage
 		}
 	}
 
 		quitMessage = c.t("Password incorrect")
 		c.Send(nil, server.name, ERR_PASSWDMISMATCH, "*", quitMessage)
 	case authFailSaslRequired, authFailTorSaslRequired:
-		quitMessage = c.t("You must log in with SASL to join this server")
+		quitMessage = c.requireSASLMessage
+		if quitMessage == "" {
+			quitMessage = c.t("You must log in with SASL to join this server")
+		}
 		c.Send(nil, c.server.name, "FAIL", "*", "ACCOUNT_REQUIRED", quitMessage)
 	}
 	if authOutcome != authSuccess {
 		c.Quit(quitMessage, nil)
 		return true
 	}
+	c.requireSASLMessage = ""
 
 	rb := NewResponseBuffer(session)
 	nickError := performNickChange(server, c, c, session, c.preregNick, rb)