Deleting current note during editing sessions results in AttributeError

[glutanimate]

Deleting the current note will close the current editor window, causing IO's call to refresh the editor to raise an AttributeError:

Debug info: 
Anki 2.1.11 (3cf770c7) Python 3.6.7 Qt 5.12.1 PyQt 5.11.3 
Platform: Mac 10.13.6 
Flags: frz=True ao=True sv=1 
Add-ons possibly involved: Image Occlusion Enhanced Alpha for Anki 21

Caught exception: 
  File "/Users/elliotreece/Library/Application Support/Anki2/addons21/1374772155/add.py", line 340, in onToHtmlCallback 
    self.ed.web.reload() 
<class 'AttributeError'>: 'NoneType' object has no attribute 'reload'

cf.: https://anki.tenderapp.com/discussions/add-ons/30847-image-occlusion-enhanced-editing-bug

[zjosua]

That's a duplicate of #87.

[glutanimate]

Whoops, you're right. Thanks for the original report and PR!