Fix null pointer exception on SendPing for non-JWT users

pkg/ping.go

@@ -8,18 +8,22 @@ import (
 // SendPing delivers the Ping message to connected subscribers.
 func (sub *Subscriber) SendPing() {
 	// Send a ping, and a refreshed JWT token if the user sent one.
-	var token string
+	var (
+		token string
+		rules map[string]bool
+	)
 	if sub.JWTClaims != nil {
 		if jwt, err := sub.JWTClaims.ReSign(); err != nil {
 			log.Error("ReSign JWT token for %s#%d: %s", sub.Username, sub.ID, err)
 		} else {
 			token = jwt
+			rules = sub.JWTClaims.Rules.ToDict()
 		}
 	}
 
 	sub.SendJSON(messages.Message{
 		Action:   messages.ActionPing,
 		JWTToken: token,
-		JWTRules: sub.JWTClaims.Rules.ToDict(),
+		JWTRules: rules,
 	})
 }