[REVIEW 3-6, 3-6-0] fdo#50345 accept empty string as scalar numeric 0 argument

[khagaroth]

>From a translators point of view, it would be no problem. The
translations are continually updated anyway. I guess it could be a
little bit annoying for people that do not use pootle, but who cares
about one untranslated string if it fixes a problem that breaks
compatibility, not to mention there are still not that many languages
that are fully translated.