Hints for libhackrf0 in main

Errors

• metainfo-license-invalid
  The MetaInfo file does not seem to be licensed under a permissive license that is in the allowed set for AppStream metadata. Valid permissive licenses include FSFAP, CC0-1.0 or MIT. Using one of the vetted permissive licenses is required to allow distributors to include the metadata in mixed data collections without the risk of license violations due to mixing incompatible licenses.We only support a limited set of licenses that went through legal review. Refer to the specification documentation for information on how to make 'GPL-2+' a valid expression, or consider replacing the license with one of the recognized licenses directly.