vim, vim-app, MacVim: remove nls variant

[ryandesign@…]

In r24862 vim's gettext support was moved to a variant. MacVim inherited this when it was created in r47370. An nls variant was also snuck into the vim-app port in r32061, though that revision was described as only adding variant descriptions; indeed, vim-app does not disable nls by default. So most vim-app users probably already have nls support, though the port does not declare a dependency on gettext.

I see no reason for natural language support to be optional. This was previously mentioned in comment:ticket:32304:4. See attached patches.

[ryandesign@…]

proposed patch for vim

[ryandesign@…]

proposed patch for vim-app

[ryandesign@…]

proposed patch for MacVim

[raimue@…]

I agree that +nls isn't really necessary and most users will already have gettext as a dependency for other ports anyway.

Thank you for your patches, committed in r87675.