message: CustomSelect: clean up css
diff: .CustomSelect__empty {
  padding: 12px 0;
  + text-align: center;
  + color: var(--text_secondary, var(--vkui--color_text_secondary));
  }
  .CustomSelect__fetching {
  align-items: center;
  justify-content: center;
  }
  -
  -.CustomSelect__empty {
  - text-align: center;
  - color: var(--text_secondary, var(--vkui--color_text_secondary));
  -}
  