Fix notice without from user
Fix notice without from user

BenoitZugmeyer/hubot-irc,Jaglag/hubot-irc,BenoitZugmeyer/hubot-irc,miyazakijunichi/hubot-irc,miyazakijunichi/hubot-irc,Spice-King/hubot-irc,nandub/hubot-irc,Jaglag/hubot-irc,Spice-King/hubot-irc,nandub/hubot-irc