Check client disconnect to exit for loop (api). Fixes #1983 (#2012)

Also update to latest melody upstream

vendor/github.com/olahol/melody/config.go

@@ -0,0 +1,22 @@
+package melody
+
+import "time"
+
+// Config melody configuration struct.
+type Config struct {
+	WriteWait         time.Duration // Milliseconds until write times out.
+	PongWait          time.Duration // Timeout for waiting on pong.
+	PingPeriod        time.Duration // Milliseconds between pings.
+	MaxMessageSize    int64         // Maximum size in bytes of a message.
+	MessageBufferSize int           // The max amount of messages that can be in a sessions buffer before it starts dropping them.
+}
+
+func newConfig() *Config {
+	return &Config{
+		WriteWait:         10 * time.Second,
+		PongWait:          60 * time.Second,
+		PingPeriod:        (60 * time.Second * 9) / 10,
+		MaxMessageSize:    512,
+		MessageBufferSize: 256,
+	}
+}