Fix call header title for direct calls

ts/components/Lightbox.tsx

@@ -422,13 +422,13 @@ export class Lightbox extends React.Component<Props, State> {
   private readonly onContextMenu = (
     event: React.MouseEvent<HTMLImageElement>
   ) => {
-    const { contentType } = this.props;
+    const { contentType = '' } = this.props;
 
     // These are the only image types supported by Electron's NativeImage
     if (
       event &&
       contentType !== 'image/png' &&
-      !contentType?.match(/image\/jpe?g/g)
+      !/image\/jpe?g/g.test(contentType)
     ) {
       event.preventDefault();
     }