Stuttering animation on Centurion Archer

On enemy centurion_projectile, it's much easier for the player to close the distance in combat, as the archer can't back away effectively.

Vanilla: https://streamable.com/2tflt OpenMW: https://streamable.com/dl8lq

OpenMW's handling of reload animation may account for some of the stop-and-start behavior here, but not all.