Holding a map cause stuttered rendering to mobs.

I found that holding a map causes a very subtle movement delay to mobs every second when looked closely, as I wrote on a previous ticket.

However, this is more noticeable on an Iron Golem and its animations.

Steps to reproduce:

1. Create an Iron Golem
2. Create a map, then look at the Iron Golem while holding it. Then compare it without holding the map.

Observed results:

The Iron Golem's animations look jittery.

Expected results:

The mob's animations and walking look normal, both with and without holding a map.