message: Use -webkit-line-clamp for the room header topic overflow
diff: @@ -141,17 +141,24 @@ limitations under the License.
  }
  .mx_RoomHeader_topic {
  + $lineHeight: $font-16px;
  + $lines: 2;
  +
  flex: 1;
  color: $roomtopic-color;
  font-weight: 400;
  font-size: $font-13px;
  + line-height: $lineHeight;
  + max-height: calc($lineHeight * $lines);
  + border-bottom: 1px solid transparent;
  +
  // to align baseline of topic with room name
  margin: 4px 7px 0;
  +
  overflow: hidden;
  - text-overflow: ellipsis;
  - border-bottom: 1px solid transparent;
  - line-height: 1.2em;
  - max-height: 2.4em;
  + -webkit-line-clamp: $lines; // See: https://drafts.csswg.org/css-overflow-3/#webkit-line-clamp
  + -webkit-box-orient: vertical;
  + display: -webkit-box;
  }
  .mx_RoomHeader_avatar {
  