perl-HTTP-Headers-Fast-0.21-bp155.2.12

- updated to 0.21
  see /usr/share/doc/packages/perl-HTTP-Headers-Fast/Changes
  0.21 2017-02-10T03:10:11Z
  - rename flatten to psgi_flatten for fixing compatibility issue plack/plack#541
    (kazeburo)
  - Copy "content_is_text" method from HTTP::Headers
    (nfg)

- initial package 0.20
  * created by cpanspec 1.78.08