`bp_get_taxonomy_types()` is wrongly skipping Group/Member type term query

[imath]

This is a regression introduced in [13312]. Casting false to an array produces array( false ) and the empty 'bp_object_terms' cache is wrongly interpreted as an array containing a false value. As a result, the query to get types saved into the db is never run, and using bp_get_taxonomy_types() always return no member/group types even if some were created.

[imath]

In 13323:

Make sure to run a type terms query when the types cache is empty

[13312] introduced a regression preventing group/member types stored as WP Terms to be retrieved.

Let's bring the right behavior back.

See #8649
Fixes #8736