message: Log nick change failures due to an invalid nickname
diff: @@ -904,9 +904,15 @@ MatrixHandler.prototype._onJoin = Promise.coroutine(function*(req, event, user)
  if (room.server.allowsNickChanges() &&
  config.getDesiredNick() === null
  ) {
  - bridgedClient.changeNick(
  - room.server.getNick(bridgedClient.userId, event.content.displayname),
  - false);
  + try {
  + const newNick = room.server.getNick(
  + bridgedClient.userId, event.content.displayname
  + );
  + bridgedClient.changeNick(newNick, false);
  + }
  + catch (e) {
  + req.log.warn(`Didn't change nick on the IRC side:${e}`);
  + }
  }
  }
  