[5.x] fix(Terms): getCreatables() throws an error if no user is authenticated.

[sbrow]

What

This simple, one-character PR changes src/Fieldtypes/Terms so that it won't throw an error if no user is authenticated when getCreatables() is called.

Why

I originally raised this issue in duncanmcclean/simple-commerce#1076. In brief, the shop / products page for my store failed to work for unauthenticated users after adding a taxonomy field to the blueprint for product variations.

This issue stems from a Statamic\Fields\Field class being created and the meta() method being invoked on it.

Whether this is a misuse of the framework, or a bug therein, I leave for you to decide.

Personally, I don't see the harm in allowing getCreatables() to work when no user is authenticated, but let me know if I'm wrong.

I have an image here of the stack trace I encountered:

Let me know if there's anything else you need from me 😄

[duncanmcclean]

Thanks for this pull request!

However, the fieldtype's preload method (which is what's calling the getCreatables method) shouldn't be getting called unless you're loading a publish form in the Control Panel, in which case there will be an authenticated user.

I haven't been able to look into the issue yet, but I imagine the fix will end up being on the Simple Commerce side.