Pullup ticket #3880 - requested by bsiegert
mk/tools: fix build problems under MirBSD

Revisions pulled up:
- mk/tools/tools.MirBSD.mk                                      1.3

---
  Module Name: pkgsrc
  Committed By: bsiegert
  Date: Fri Jul 27 12:53:26 UTC 2012

  Modified Files:
  pkgsrc/mk/tools: tools.MirBSD.mk

  Log Message:
  Use /usr/bin/true instead of : for true. The latter is incompatible with
  the use of a colon as a separator, such as in
  sed "s:@FOO@:${FOO}"

  This unbreaks a variety of packages in MirBSD.

(tron)