Steps to reproduce:

1) Open the scene `TestScene1`
2) Ensure that Auto mode is on for lighting
3) In hierarchy, choose the game object called `EmissiveObject`
4) Open the material settings and change the emission color.
5) Observe the bug. Even though the Global Illumination parameter is set to None, it restarts the baking process.

Notes:
- The emissive color seems to always be part of the material hash without checking the actual state of the global illumination flag.
- Reproduced in 5.1.5f1, 5.3.5f1, 5.3.5p8, 5.3.6f1, 5.4.0f1, 5.4.0f3, 5.5.0b5, 5.6.0a1