Fix error when no connection

shelly/syncscript.js

@@ -137,8 +137,13 @@ function sendToZoblak() {
       "body": JSON.stringify(payload)
     },
     function(result) {
+      if (result) { 
         print("server says: ", result.code);
        }
+       else {
+         print("There is no server response present. Check connection!")
+       }
+    }
   );
 
 }