Standard shader inspector's namespace was changed

but the reference inside the shader was not

Author: keveleigh

Assets/MixedRealityToolkit/_Core/Resources/Shaders/MixedRealityStandard.shader

@@ -738,5 +738,5 @@ Shader "Mixed Reality Toolkit/Standard"
     }
 
     FallBack "VertexLit"
-    CustomEditor "Microsoft.MixedReality.Toolkit.Inspectors.MixedRealityStandardShaderGUI"
+    CustomEditor "Microsoft.MixedReality.Toolkit.Core.Inspectors.MixedRealityStandardShaderGUI"
 }