Fauxton "Edit string" dialogue blank for certain kinds of keys

[xristy]

If a key starts with @ or contains a : then the Edit string dialogue in Fauxton (CouchDB v. 2.0.0) displays blank with title Edit Value, and Cancel and Modify Text buttons (see attached screenshot). Here's a simple document that illustrates the issue:

{
  "_id": "93a894752babfcb3fd07989762001a9e",
  "_rev": "2-2b6698e2d720a3476d9c857fafe50abb",
  "@graph": [
	{
	  "rdfs:label": [
		{
		  "@language": "bo-x-ewts",
		  "@value": "grub thob"
		},
		{
		  "@language": "en",
		  "@value": "mahasiddha"
		}
	  ],
	  "@id": "top:T10MS14283",
	  "@type": "top:Topic",
	  "note": {
		"@id": ":T10MS14283_Note1",
		"@type": "Note",
		"note_content": {
		  "@language": "en",
		  "@value": "this topic is applied in reference to a siddha or mystic adept, singularly or in any of their enumerated groupings"
		}
	  },
	  "top:status": "released"
	}
  ]
}

Put the cursor in the key or value fields for an item such as "@value" or "top:status" and then select the Edit string button on the left of the item and a blank dialogue will appear:

Remove the @ or : and then select the Edit string button on the left of the item and a normal Edit Value dialogue will open: