multimedia/libv4l: unbreak clean build after r556854

> Configuring for libv4l-1.20.0

Can't exec "autopoint": No such file or directory at /usr/local/share/autoconf-2.69/Autom4te/FileUtils.pm line 345.
autoreconf-2.69: failed to run autopoint: No such file or directory
autoreconf-2.69: autopoint is needed because this package uses Gettext

• Error code 1

PR: 251548
Submitted by: m.ne@gmx.net