`/communities/create` sends `undefined` request to the API

[MMilosz]

Describe the bug

When creating a new top level Community, devtools show that the app sends the following undefined request to the server:

[server URL]/api/core/communities/undefined?embed=logo&embed=subcommunities&embed=collections&embed=parentCommunity

Issue discovered on both sandbox.dspace.org and demo.dspace.org

To Reproduce

1. Log in as admin
2. Open devtools, go to the network tab
3. From the sidebar, select New > Community (or go directly to the /communities/create). Press the 'Create a new top-level community'
4. Observe the undefined request sent to the backend

Expected behavior

No undefined request being send

Related work

Nothing found

[lgeggleston]

Thanks @MMilosz! Verified this on demo.dspace.org, hopefully would be a small cleanup fix. Ready for a volunteer developer to pick up.