fix display of broken videos

src/lib/formatters.js

@@ -236,8 +236,6 @@ function handleVideoData(el, data, attr) {
     if (data.ref || data.val) {
       attr.onClick = this.onVideoPreview;
       attr.loading = 'lazy';
-    } else {
-      attr.src = null;
     }
     el = InlineVideo;
   } else {

src/widgets/inline-video.jsx

@@ -27,11 +27,12 @@ export default class InlineVideo extends React.PureComponent {
     return (
       <div className={className}>
         {React.createElement('img', this.props)}
+        <div className="play-control">
         {this.props.onClick ?
-          <div className="play-control">
-            <i className="material-icons white bigger">play_arrow</i>
-          </div>
-          : null}
+          <i className="material-icons white bigger">play_arrow</i>
+          :
+          <img src="img/broken_video.png" width="36" height="36" />}
+        </div>
         {duration ? <div className="duration">{duration}</div> : null}
       </div>
     );