WASHINGTON (Reuters) - U.S. House Speaker Paul Ryan on Thursday said he had a good conversation with presumptive Republican presidential nominee Donald Trump, but he had no comment on his possible endorsement of the party’s likely nominee.  “We had a very good and very productive phone call,” Ryan told reporters, referring to a telephone call the two men had Wednesday night. (This version of the story has been corrected to say presumptive nominee, not presumptive candidate, in first paragraph) 