Reproduction steps:

1. Open "Camera MSAA checkbox changes other cameras' rendering order" project
2. Enter Play mode
3. Select GameObject "C"
4. "Allow MSAA" in the Inspector

Expected Result: Camera render order shouldn't change when MSAA is allowed on a camera, but MSAA is disabled in the Project Settings
Actual Result: Camera order changes when MSAA is allowed on a camera, but disabled in the Project Settings

Reproduced with: 2018.3.0a1, 2018.2.0b7, 2018.1.4f1, 2017.4.5f1, 2017.3.2f1, 2017.2.3f1, 2017.1.4p1