Merge remote-tracking branch 'origin/stable'

# Conflicts:
#	src/services/ws.js

src/public/app/widgets/attribute_widgets/attribute_editor.js

@@ -166,6 +166,7 @@ const editorConfig = {
         'IncludeNote',
         'CutToNote',
         'Mathematics',
+        'AutoformatMath',
         'indentBlockShortcutPlugin',
         'removeFormatLinksPlugin'
     ],

src/services/ws.js

@@ -79,6 +79,10 @@ function fillInAdditionalProperties(entityChange) {
     // the exception is isDeleted - in that case becca doesn't contain such entity at all
     // this would have to be handled separately
 
+    if (entityChange.isErased) {
+        return;
+    }
+
     // fill in some extra data needed by the frontend
     if (entityChange.entityName === 'attributes') {
         entityChange.entity = sql.getRow(`SELECT * FROM attributes WHERE attributeId = ?`, [entityChange.entityId]);