WASHINGTON (Reuters) - A U.S. Senate panel has rescinded a subpoena that would have forced Paul Manafort, a former campaign manager of President Donald Trump, to appear at a hearing on Wednesday as part of its probe into Russia's role in the 2016 presidential election. Manafort is going to "continue discussions" with Senate investigators, a source familiar with the issue told Reuters. Another source said the subpoena was rescinded because the Senate Judiciary Committee was still negotiating with Manafort on document production and a later appearance.