message: Null-guard for newTag
diff: @@ -313,7 +313,7 @@ module.exports = React.createClass({
  const newOrder = {};
  // Is the tag ordered manually?
  - if (!newTag.match(/^(m\.lowpriority|im\.vector\.fake\.(invite|recent|direct|archived))$/)) {
  + if (newTag && !newTag.match(/^(m\.lowpriority|im\.vector\.fake\.(invite|recent|direct|archived))$/)) {
  const newList = Object.assign({}, this.state.lists[newTag]);
  // If the room was moved "down" (increasing index) in the same list we
  