Log Message:
p5-libwww: update to 6.31.

6.31      2017-12-11 01:55:53Z
    - fix version numbering (RT#123841)

6.30      2017-12-07
    - Use tr/// instead of s/// where appropriate (Ville Skyttä) (GH #265)
    - Use parent -norequire instead of base to not look for external
      dependencies (Fabian Zeindler) (GH #259)
    - Fix run_handlers to allow assigning to the request / response (Gianni
      Ceccarelli) (GH #274)