Update devel/py-argcomplete to 1.4.1.

Version 1.4.1 (2016-06-14)
- activate-global-python-argcomplete runs on Homebrew out of the box

Version 1.4.0 (2016-06-10)
- Correctly handle suggestions for positionals with variable-length
  nargs. Thanks to @evanunderscore (#132, #133).

(fhajny)