Fix: Tag taxonomy returns empty array

[Koli14]

Based on @julesrenaud answer: #245 (comment)

[airesvsg]

Hi @Koli14,

Thanks for your PR.

You've tried to use hide_empty in your endpoint?

http://localhost/wp-json/acf/v3/categories?hide_empty=0

Thanks

[Koli14]

Sorry, the PR Title is misleading: Here is my Issue detail:
If I visit /wp-json/wp/v2/tags/471 there is no ACF field. By a Category or a Custom Taxonomy, it's working (e.g /wp-json/wp/v2/categories/4 or wp-json/wp/v2/folders/4. If I go to /wp-json/acf/v3/tags it's an empty array, but working for Categories or Custom Taxonomy. If I visit /wp-json/acf/v3/tags/471, then it has an ACF field as exepted.

[Koli14]

@airesvsg pls consider to merge my pull request.

[Koli14]

Pls consider to merge this PR!