Crash logs indicate it's possible for `u2fCmd` to be null.
<rdar://problem/124475802>
*** This bug has been marked as a duplicate of bug 270876 ***
Re-opening for pull request https://github.com/WebKit/WebKit/pull/25790
*** Bug 270876 has been marked as a duplicate of this bug. ***
Committed 276002@main (9e273ba79831): <https://commits.webkit.org/276002@main> Reviewed commits have been landed. Closing PR #25790 and removing active labels.