Renamed Spawn Egg's Endermites despawn after 2 minutes

Steps to reproduce:

1. Get in a creative world
2. Take a Endermite Spawn Egg, and rename it with any name you want
3. Spawn the endermite, and wait...

If the endermite is named via the spawn egg, it despawns anyway, but if it's named later with a nametag, it won't despawn.