WASHINGTON (Reuters) -Italian Prime Minister Mario Draghi said on Wednesday he was confident Moscow’s demand that European buyers pay for Russian gas in roubles will not lead to a disruption of supplies. The European Commission has warned that complying with Russia’s scheme might breach EU sanctions, but Draghi said it was a “grey zone” with no official ruling on the matter. Speaking during a visit to the United States, Draghi said he was “quite confident” about the supply situation for “a silly reason” that there was a lack of clarity on the rules after Russia’s invasion of Ukraine in Februar…