Checkmk Werk 12942: REST API: parse HTTP content-type header options

ID: 12942 Title: REST API: parse HTTP content-type header options Component: Core & setup Level: 1 Class: Bug fix Version: 2.1.0i1 Endpoints of the REST API didn't understand content-types in the form of "application/json; charset=utf-8" and rejected the call even if it would be valid according to the RFC. This has now been fixed and the error messsages have been improved as well.