The NavMesh Surface Build Volume is visible when the component is off or when the component is deselected

To reproduce:
1. Open attached project
2. Open 1.unity scene
3. Observe scene view
Expected result: Only Cube/Camera is visible
Actual result: There's a red wire frame showing the NavMesh surface volume visible.

Note: If you select the object, the wire frame get's transparent walls. This should be invisible when Navigation tab is not selected (or never at all, since you disabled the object)

Reproduced in:
Version 5.4.0a6 (8e1942ed5322)
Fri, 11 Dec 2015 14:25:49 GMT
Branch: ai/navmesh/builder