A drunk off-duty corrections officer openly carrying a handgun was shot in the arm by police early this morning after he refused to drop his weapon, police said. Plainclothes cops fired at Rikers Island guard Victor Hernandez, 35, at about 4 a.m. this morning after he ignored orders to relinquish the weapon and aimed it in their direction when they stopped him on 3rd Avenue, off 161st Street, police and witnesses said. "He turned, pointed and they reacted," a source said. Hernandez, who aimed his loaded 9mm Glock at the badge-wearing officers, was struck in the left arm, sources said....