message: FormLayoutGroup: simplify removable selector
diff: padding: 12px var(--formitem_padding);
  }
  -.FormLayoutGroup--horizontal.FormLayoutGroup--removable {
  - padding-left: 0;
  - padding-right: 0;
  -}
  -
  .FormLayoutGroup__removable {
  flex-grow: 1;
  min-width: 0;
  .FormLayoutGroup--ios {
  --formitem_padding: 12px;
  }
  +
  +.FormLayoutGroup--removable {
  + padding-left: 0;
  + padding-right: 0;
  +}
  