Type error in `bp_remove_member_type()`

[imath]

See ​https://buddypress.org/support/topic/bug-in/ for a full description.

[imath]

In 13239:

Make sure member has a type before trying to remove one

Avoid a PHP Type error if the member has no member types and the Administrator (or more probably a plugin) tries to remove it.

Props sx1001

See #8639 (trunk)

[imath]

In 13240:

Make sure member has a type before trying to remove one

Avoid a PHP Type error if the member has no member types and the Administrator (or more probably a plugin) tries to remove it.

Props sx1001

Fixes #8639 (branch 10.0)