To reproduce:
1. Open repro project (link in edit comments)
2. Open 'Test Stage 1' scene
3. Find Main Camera in the Hiearchy
4. Activate Post Processing Behaviour
5. Observe that zooming in and out in Game view increases the brightness of halo textures attached to point lights.
It is worth noting that all the effects in the post processing asset are disabled.

Expected: the intensity of halo textures attached to point lights should remain the same
Actual: toggling post processing behaviour and zooming in and out in game view changes the brightness intensity of point lights

Notes:
- Reproduced on: 5.6.0p3, 2017.1.0b2
- Not reproducible on: 5.5.3p2, 5.6.0p1
- Please check the latest image attached below