gettext-full: prevent using emacs

gettext-full: prevent using emacs

When the gettext-full host build phase finds an `emacs` exectuble during the
build it will launch an `emacs --batch` command to run some Lisp code.

On certain Debian systems the `/usr/bin/emacs` path might point, via
alternatives, to the `/usr/bin/jove` editor which will then launch an
interactive session when invoked by the gettext build.

In order to avoid this problem, explicitely disable emacs handling during
the build through a configure environment variable.

Also remove my now unreachable maintainer address.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>