When selecting a gameobject that contains a cloth component, if the gameobject is disabled then the Editor will throw an error.

Reproduction steps:
1. Open the scene "Scene" in the attached project
2. Select the "Plane" gameobject
3. Observe the following errors in the Console:
Mesh.colors is out of bounds. The supplied array needs to be the same size as the Mesh.vertices array.
UnityEditor.ClothInspector:OnEnable()

IndexOutOfRangeException: Array index is out of range.
UnityEditor.ClothInspector.SetupSelectedMeshColors () (at D:/UnityDEV/5.0-branch/Editor/Mono/Inspector/ClothInspector.cs:356)
UnityEditor.ClothInspector.OnEnable () (at D:/UnityDEV/5.0-branch/Editor/Mono/Inspector/ClothInspector.cs:266)

Expected result:
Disabled cloth objects shouldn't throw errors.

Reproducible in versions 5.4.3f1, 5.5.0f1, and 5.6.0a4.