License name cannot be recognized automatically

[tmehnert]

I'm using CycloneDX and Dependency Track to track my dependencies. Sadly the license of msgpack-java could not be recognized automatically because the license name APL2 is unknown. This will cause additional efforts for manual auditing.

Proposal

Change the license name to the SPDX-ID of the Apache 2.0 license. This would it make easier für license tracking systems to recognize the license of this project. I will provide a PR for this.