NullReferenceExceptions are thrown continuously on removing VFX Render component from Visual Effect Graphs prefab asset.

Steps to repro:
1. Open the attached Project.
2. Select Visual Effect > Create its prefab.
3. Select the prefab asset.
4. Remove VFX-Renderer component.

Actual Result:
NullReferenceExceptions error in the console.

Expected Result:
No error in the console.

Reproducible in:
2020.1.0a18, 2019.3.0f5 (fe220cd6911a), 2019.3.0a10.

Tested with Package Version: 7.1.7, 7.1.6, 7.1.1, 7.0.0.

Environment:
Occurs on Windows and Mac.

Stack trace:
NullReferenceException: Object reference not set to an instance of an object
UnityEditor.VFX.VisualEffectEditor.DrawRendererProperties () (at library/packagecache/com.unity.visualeffectgraph@7.1.7/editor/inspector/visualeffecteditor.cs:1105)
UnityEditor.VFX.VisualEffectEditor.OnInspectorGUI () (at library/packagecache/com.unity.visualeffectgraph@7.1.7/editor/inspector/visualeffecteditor.cs:759)
UnityEditor.VFX.AdvancedVisualEffectEditor.OnInspectorGUI () (at library/packagecache/com.unity.visualeffectgraph@7.1.7/editor/inspector/advancedvisualeffecteditor.cs:147)
UnityEditor.UIElements.InspectorElement+<>c__DisplayClass55_0.<CreateIMGUIInspectorFromEditor>b__0 () (at <065cf923b7714278a3c7baf218a9b966>:0)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)