HTTP Consumer - content type error on new nodes

## Steps to reproduce
1. Add a new node **"HTTP Consumer"**
2. Fill in the URL

3. Run the workflow
4. The node returns the following error:
**"undefined contentType not supported by this component"**

## Workaround
1. Open the **Content Type** dropdown and change the value to anything other than `"application/json"`
2. Save and close the node configuration window
3. Reopen the node configuration
4. Select `"application/json"` again

Start by locating the HTTP Consumer node implementation and its configuration handling, then reproduce the workflow described in the issue with a new node and a URL. Done means a new node can run with the default application/json content type without producing an undefined-contentType error, while the existing workaround remains unnecessary.

Written by the indexing model from the issue text.