fix(files): disable containment in header

Signed-off-by: Varun Patil <varunpatil@ucla.edu>

apps/files/src/components/FilesListVirtual.vue

@@ -332,7 +332,6 @@ export default Vue.extend({
 
 		// Before table and thead
 		.files-list__before {
-			contain: style paint layout;
 			display: flex;
 			flex-direction: column;
 		}