message: Fix tabbing through room sublist
diff: @@ -128,7 +128,7 @@ const RoomSubList = createReactClass({
  this._headerButton.current.focus();
  },
  - onKeyDown: function(ev) {
  + onHeaderKeyDown: function(ev) {
  switch (ev.key) {
  case Key.TAB:
  // Prevent LeftPanel handling Tab if focus is on the sublist header itself
  @@ -297,7 +297,7 @@ const RoomSubList = createReactClass({
  }
  return (
  - <div className="mx_RoomSubList_labelContainer" title={title} ref="header">
  + <div className="mx_RoomSubList_labelContainer" title={title} ref="header" onKeyDown={this.onHeaderKeyDown}>
  <AccessibleButton
  onClick={this.onClick}
  className="mx_RoomSubList_label"
  @@ -391,7 +391,6 @@ const RoomSubList = createReactClass({
  className={subListClasses}
  role="group"
  aria-label={this.props.label}
  - onKeyDown={this.onKeyDown}
  >
  { this._getHeaderJsx(isCollapsed) }
  { content }
  