Bone Hierarchy not updated when reimporting skeletal mesh

Bone Hierarchy not updated when reimporting skeletal mesh.

Now, I get that updating the skeleton hierarchy could be disastrous if you had another mesh using the same skeleton and that it'd be really risky.

An alternative may be to warn the user when attempting to overwrite a skeletal mesh when the new FBX doesn't match the existing hierarchy.

1. Download the attached Zip file. You'll find Original and Modified FBX files inside.
2. Import the Original FBX
3. Note the hierarchy under Spine3 (should go Bag, SpineTop, Bag_RtBodyStrap...in that order)
4. Select "Import" in the Content Browser and grab the Modified FBX
5. Select Yes in the Overwrite window
6. Use default import settings
7. Open the mesh

Result: The hierarchy under Spine3 is the same.
Expected: Hierarchy under Spine3 is Bag_RtBodyStrap, Bag, SpineTop