message: fix: rollback default top value for FixedLayout
diff: @@ -46,7 +46,7 @@ export interface FixedLayoutContext {
  class FixedLayout extends React.Component<FixedLayoutProps, FixedLayoutState> {
  state: FixedLayoutState = {
  position: 'absolute',
  - top: 0,
  + top: null,
  width: '',
  };
  