[Commits] [wesnoth/wesnoth] a52cc3: scons: Fix blowing up with OS_ENV=true

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/wesnoth/wesnoth
  Commit: a52cc353dfde491e978a04d45000b5a1cfb1baf3
      https://github.com/wesnoth/wesnoth/commit/a52cc353dfde491e978a04d45000b5a1cfb1baf3
  Author: loonycyborg <loonycyborg at gmail.com>
  Date:   2015-04-07 (Tue, 07 Apr 2015)

  Changed paths:
    M scons/pango.py
    M scons/pkgconfig.py

  Log Message:
  -----------
  scons: Fix blowing up with OS_ENV=true

If PKG_CONFIG_PATH was unset it was effectively trying to set this
os.environ variable to None which os.environ doesn't allow.