Update to 1.978
    
    - New upstream release 1.978
      - Added public prefix checking to verification of wildcard certificates, e.g.
        accept *.foo.com but not *.co.uk; see documentation of
        SSL_verifycn_publicsuffix and IO::Socket::SSL::PublicSuffix
      - Fix publicsuffix for IDNA, more tests with various IDNA libs
        (CPAN RT#94424)
      - Reuse result of IDN lib detection from PublicSuffix.pm in SSL.pm
      - Add more checks to external/usable_ca.t; now it is enough that at least one
        of the hosts verifies against the built-in CA store
      - Add openssl and Net::SSLeay version to diagnostics in load test
    - Switch preferred IDN back-end from Net::LibIDN to URI::_idna as per upstream,
      falling back to Net::IDN::Encode on older distributions
    - Add fix from upstream git to support building with Test::More < 0.88