fix(files): better null relatedTarget event detection

Co-authored-by: Ferdinand Thiessen <opensource@fthiessen.de>

Signed-off-by: John Molakvoæ <skjnldsv@users.noreply.github.com>

Signed-off-by: nextcloud-command <nextcloud-command@users.noreply.github.com>

[skip ci]

apps/files/src/components/DragAndDropNotice.vue

@@ -126,7 +126,7 @@ export default defineComponent({
 			// only when we're leaving the current element
 			// Avoid flickering
 			const currentTarget = event.currentTarget as HTMLElement
-			if (currentTarget?.contains((event.relatedTarget || event.target) as HTMLElement)) {
+			if (currentTarget?.contains((event.relatedTarget ?? event.target) as HTMLElement)) {
 				return
 			}