don't hammer server if conn terminated during reconnection

irc.go

@@ -242,7 +242,8 @@ func (irc *Connection) Loop() {
 		}
 		irc.Wait()
 		for !irc.isQuitting() {
-			irc.Log.Printf("Error, disconnected: %s\n", err)
+			irc.Log.Printf("Error, disconnected: %s, 15s backoff\n", err)
+			time.Sleep(15 * time.Second)
 			if err = irc.Reconnect(); err != nil {
 				irc.Log.Printf("Error while reconnecting: %s\n", err)
 				time.Sleep(60 * time.Second)