Fixed chapter moves crashing history page due to changes in change reporting in 2.0.

marko/page/data/components/change/component.js

@@ -65,8 +65,8 @@ module.exports = class {
         
         this.state.operation += " chapter"
         this.state.links = [{
-          text: chapter.title || `Untitled chapter (${chapterKey.id})`,
-          href: `/story/${storyKey.id}#${chapterKey.id}`,
+          text: (chapter||{}).title || `Untitled chapter (${(chapterKey||chapter).id})`,
+          href: `/story/${storyKey.id}#${(chapterKey||chapter).id}`,
         }]
 
         break