Deleting a content browser asset while that asset is open causes all other open assets to close.

If multiple assets are open (blueprints, materials, particle system, etc.), deleting one of the assets from the content browser causes all other open asset windows to close.

1. Open UE4 Editor
2. Add 3 blueprints based on actor and open them in the blueprint editor
3. Delete one of the blueprints from the content browser

Result:
The other two blueprint windows close when one is deleted

Expected:
Only the window for the deleted blueprint closes