[Bug]: Editing a community deletes it

[AToska21]

Checked Existing

• I have checked the repository for duplicate issues.

What happened?

When I was messing around with the Juxt admin panel, I noticed that whenever I edited a community, it disappeared. This happened because of the parent community ID. On community creation, it is set to "null". But when editing a community, it is set to '', not null. This makes Juxt, and in extension the miiverse API, think it has a parent community, and stop displaying it at all.

What did you expect to happen?

It would keep the parent community ID the same, and not change it unless the textbox itself changed.

Steps to reproduce?

1. Have an account that can edit communities.
2. Edit a community, but just click "save".
3. It disappears completely, and can only be restored by changing the database.

Other relevant information. (OPTIONAL)

No response