Helper/Nix.pm: perlcritic statsd in scalar context

Dependencies

• [2] 5DXGOH6Q statsd: add a chance to set hostname and port in hydra.conf
• [3] AFTXA575 * $HYDRA_DATA environment variable.
• [4] 4H6FVIWG hydra-notify: make the prometheus endpoint configurable, default-off
• [*] 2GK5DOU7 * Downloading closures.

Change contents

• replacement in src/lib/Hydra/Helper/Nix.pm at line 69
  [2.530]→[2.530:625](∅→∅)
  − "host" => %statsd{'host'} // 'localhost',

  − "port" => %statsd{'port'} // 8125,
  [2.530]

  [2.625]
  + "host" => $statsd{'host'} // 'localhost',

  + "port" => $statsd{'port'} // 8125,