Update CPANPLUS::Dist::Build to cpan version 0.46

Update CPANPLUS::Dist::Build to cpan version 0.46

  Extract from Changes file
  =========================

  0.46 Sat Jan 23 07:52:19 GMT 2010
    - actually make the prereq resolving fallback to _build/ querying
      if the 'prereq_data' action fails. *facepalm*

Resolves an issue in prereq resolution where the failure of using
'Build prereq_data' would not fallback to querying _build/ data.

Highlighted by EekBoek distribution which bundled an older version of
Module::Build.