message: hopefully fix NPE on toLowerCase
diff: @@ -303,7 +303,9 @@ module.exports = React.createClass({
  } : {};
  return this._matrixClient.register(
  - this.state.formVals.username.toLowerCase(),
  + (this.state.formVals.username ?
  + this.state.formVals.username.toLowerCase() :
  + this.state.formVals.username),
  this.state.formVals.password,
  undefined, // session id: included in the auth dict already
  auth,
  