gplugin/gplugin

Use a different (hopefully correct) Perl path on FreeBSD.
develop
2020-02-29, Elliott Sales de Andrade
43e4a29d523e
Use a different (hopefully correct) Perl path on FreeBSD.

Also, switch to expanded versions of those variable (*archexp).
The following individuals have contributed to this project.
Ankit Vani <a@nevitus.org>
EionRobb <eion@robbmob.com>
Elliott Sales de Andrade <quantum.analyst@gmail.com>
Gary Kramlich <grim@reaperworld.com>
Jason Scherer <schereja@gmail.com>
John Bailey <rekkanoryo@rekkanoryo.org>
Mike Ruprecht <cmaiku@gmail.com>
Olaf Hering <olaf@aepfle.de>
Richard Laager <rlaager@pidgin.im>