what reasons does ulrich give as to why he had a change of heart and no longer wanted to be enemies with georg

I think that Ulrich offering a glass of wine to Georg was a peace offering. Ulrich had watched Georg drown under pain and exhaustion. Ulrich too was tired of quarrelling and fighting. Finally Ulrich would try to reconcile, "Neighbor, if you will help bury the old quarrel, I will ask you to be my friend."