message: change roster toggle handler
diff: }
  .jsxc-roster-toggle {
  - background-color: transparent;
  + background-color: rgba(225, 225, 225, 1);
  + border-radius: 14px 0 0 14px;
  cursor: pointer;
  - height: 100%;
  - left: -14px;
  + height: 44px;
  + margin-top: -22px;
  position: absolute;
  - top: 0;
  + right: 100%;
  + top: 50%;
  + transition: width 0.5s, background-color 0.5s;
  width: 14px;
  z-index: 110;
  + &::after {
  + border: 8px solid rgba(0, 0, 0, 0.2);
  + border-bottom-color: transparent;
  + border-left-color: transparent;
  + border-left-width: 0;
  + border-top-color: transparent;
  + content: " ";
  + height: 0;
  + left: 50%;
  + margin-left: -4px;
  + margin-top: -7px;
  + pointer-events: none;
  + position: absolute;
  + top: 50%;
  + width: 0;
  +
  + .jsxc-roster-shown & {
  + transform: rotate(180deg);
  + }
  + }
  +
  &:hover {
  - background-color: $roster-toggle-hover;
  + background-color: rgba(200, 200, 200, 1);
  + width: 28px;
  }
  }
  