Blender Git Loki

Fix T82624: Skin modifiers root bone cannot be moved

When creating an armature from the skin modifier, resulting bones would
always be flagged BONE_CONNECTED.
Those bones cannot be transformed (just rotated).

Now only flag bones that really have a parent BONE_CONNECTED.

Maniphest Tasks: T82624

Differential Revision: https://developer.blender.org/D9534