Add fallback translation back

[pedroborges]

Without the fallback translation, the text defined on the section headline in the blueprint is never used.

[medienbaecker]

I changed this because I found an English fallback for non-translated languages to be better. If you provide a fallback, the variable modules.empty is used instead of the English translation:

'empty' => function ($empty = 'modules.empty') {
  return I18n::translate($empty, $empty);
}

'empty' => function ($empty = 'modules.empty') {
  return I18n::translate($empty);
}

I would suggest using something like this to make sure you can overwrite it in the blueprint but still have the English fallback:

'empty' => function ($empty = null) {
  return $empty ? $empty : I18n::translate('modules.empty');
}

What do you think, @pedroborges?

[pedroborges]

@medienbaecker Totally makes sense, I have updated my PR.