message: Fix an error where React doesn't like value=null on a select
  This only happens when there are no canonical aliases for a room.
diff: @@ -220,8 +220,9 @@ module.exports = React.createClass({
  let canonical_alias_section;
  if (this.props.canSetCanonicalAlias) {
  let found = false;
  + const canonicalValue = this.state.canonicalAlias || "";
  canonical_alias_section = (
  - <select onChange={this.onCanonicalAliasChange} value={this.state.canonicalAlias}>
  + <select onChange={this.onCanonicalAliasChange} value={canonicalValue}>
  <option value="" key="unset">{ _t('not specified') }</option>
  {
  Object.keys(self.state.domainToAliases).map((domain, i) => {
  