Use injector topic in the url http request node

[Andrei]

Perhaps this thread can clarify

HTTP request node - query string

The http request node was greatly improved in Node-REd version 0.20 with the addition of Bearer and Digest authentication modes. Additionally, a new option was added to allow building a query string from msg.payload. This is explained in the release notes as quoted below: The HTTP Request node can optionally automatically encode msg.payload as query string parameters for a GET request. What is missing perhaps is a quick note in the help text explaining that msg.payload in such case is expec…