message: Fix vector-im/riot-web#2833 : Fail nicely when people try to register numeric user IDs
diff: @@ -203,7 +203,19 @@ class Register extends Signup {
  } else if (error.errcode == 'M_INVALID_USERNAME') {
  throw new Error("User names may only contain alphanumeric characters, underscores or dots!");
  } else if (error.httpStatus >= 400 && error.httpStatus < 500) {
  - throw new Error(`Registration failed! (${error.httpStatus})`);
  + let msg = null;
  + if (error.message) {
  + msg = error.message;
  + }
  + else if (error.errcode) {
  + msg = error.errcode;
  + }
  + if (msg) {
  + throw new Error(`Registration failed! (${error.httpStatus}) - ${msg}`);
  + }
  + else {
  + throw new Error(`Registration failed! (${error.httpStatus}) - That's all we know.`);
  + }
  } else if (error.httpStatus >= 500 && error.httpStatus < 600) {
  throw new Error(
  `Server error during registration! (${error.httpStatus})`
  