Cannot Complete RequestToken Phase of Code Grant OAuth2 Flow

I've been trying to complete integration with the JetBrains Hub OAuth2 provider utilizing the Jersey OAuth2 Code Grant flow.

When it comes to the request for Token from the Hub (providing a valid code and state), the Hub returns with a 401 NOT AUTHORIZED response.

Investigating a bit further, it appears that they are expecting an Authorization header encoding the Client Id and Client Secret with the finish phase of the Code Grant Flow. ([https://youtrack.jetbrains.com/issue/JPS-3030](https://youtrack.jetbrains.com/issue/JPS-3030))

They reference the following section of the spec: [http://tools.ietf.org/html/rfc6749#section-4.1.3](http://tools.ietf.org/html/rfc6749#section-4.1.3)
#### Environment
WIndows & Mac OSX
#### Affected Versions
[2.22.2]