Update to 0.51
    
    - New upstream release 0.51
      - Switch to v1 API
        - Old complex query forms may stop working with new API
      - Stop relying on . being in @INC
      - Drop URI::Escape prereq
      - Switch from JSON to JSON::MaybeXS
      - Test clean-ups
    - This release by HAARG → update source URL
    - Make %files list more explicit
    - Drop redundant Group: tag and %{?perl_default_filter}