Update for Blender 2.81+

[sburris0]

mesh.update() was changed to only take two positional arguments in 2.81.
Docs here.

[unelsson]

I can confirm that this change prevents a crash in 2.82 too. I was able to export at least the geometry to .dae format.

[aggregate1166877]

Hi there, just exported a project in Blender 2.83 using this commit. No problems; materials, objects, and animations with loc/rot/scale keyframes came across fine.

Also tried a scene with 2 million verts, no problems.