message: Properly set style attribute on shared usercontent iframe
  Fixes
diff: @@ -43,9 +43,8 @@ function getManagedIframe(): { iframe: HTMLIFrameElement, onLoadPromise: Promise
  // Dev note: the reassignment warnings are entirely incorrect here.
  - // @ts-ignore
  - // noinspection JSConstantReassignment
  - managedIframe.style = { display: "none" };
  + managedIframe.style.display = "none";
  +
  // @ts-ignore
  // noinspection JSConstantReassignment
  managedIframe.sandbox = "allow-scripts allow-downloads allow-downloads-without-user-activation";
  