MUNICH (Reuters) - Twitter is much more than a social network and has no time to waste worrying about newcomers like Google+ as it becomes more important as an information service and builds its advertising business, co-founder Jack Dorsey said on Sunday. "We have a lot to concern ourselves with, just building Twitter," Dorsey said when asked at a technology conference whether he was worried that Google's own fledgling social network would come after Twitter. "Social is just one part of what we do. ...