Update to 3.43

Upstream changes:
version 3.43: Tue Feb 16 16:53:26 UTC 2021
        - admin: update copyright, move from rt.cpan.org (retired) to github
        - rt.cpan.org#132720: compress: Readmethod: avoid false-positive EOF
          [Eric Wong]
        - rt.cpan.org#129920: Parsing headers fails under special condition
          [Jens Berthold]
        - rt.cpan.org#132654: avoid cyclic reference on ->compress
          [Eric Wong]
        - rt.cpan.org#132380: append_string can fail to match APPENDUID in response
          [Radom鱈r Pol叩ch]
        - rt.cpan.org#133496: allow for undocumented BODYSTRUCTURE extensions
          [Rhesa Rozendaal]

(wen)