Blender Git Loki

Fix T72905: EEVEE + UV Edit Unused Map

There is a cornercase when the user edits an uvmap, that is not part of
the material (yet). When this is the case the uvmap was not added to the
uv buffer and the 'pos' alias was not created.

This change will always request the active uv map when uv editing.

Reviewed By: fclem

Differential Revision: https://developer.blender.org/D6534