Don't assume a request has an authorization header

This assumption that the authorization header may not exist should also be applied further to the content-type header that comes in the next block of code. Because of this, I'm proposing an alternate patch rolled against the 2.x-dev branch.

I've made a small adjustment to ensure that we don't perform a trim on a null value by using a null coalescing operator. I think this is also closer to the coding style of the original author.

This change in this patch will pass an empty value directly to trim if no authorization or content-type header is passed.

This seems to have been fixed as part of the giant Drupal 10 compat PR.