Regression: CDN host used in preview Page Model API

In the preview mode (Channel Manager), links to images were using the CDN host that is specified, which caused the images to not load.

The problem seems to be in HstLinkImpl.toUrlForm(..) method. In that method there is an if-else statement:

if (requestContext.isChannelManagerPreviewRequest() && !requestContext.isPageModelApiRequest()) {
    // some code
}
else {
    // code to prefix url with CdnHost if not blank
    ...
    // more code
}

In case of a client's SPA++ implementation, the React application requests the preview version of the 'resourceapi', so it is both a ChannelManagerPreviewRequest and a PageModelApiRequest, so it ends up in the 'else' part of the statement.

This used to work in 13.