I did a google and was surprised to find a 19th century (?) instance of the name, here-
http://www.bergischer-kalender.de/baende.aspx?id=GThough I can't learn anything from the context, having no German.
I was working on the assumption that it was a German attempt at a non-German surname. I was going to suggest the French Goutiere, which could be occupational and connected to the building trade, or Dutch Goedheer/Goetheer, which might be a description or a nickname. Gutherr would be a translation of Goedheer.