BEIRUT/QAMISHLI, Syria, (Reuters) - The Syrian government and the Kurdish-led Syrian Democratic Forces have been holding negotiations at a Russian airbase in Syria, a Syrian Kurdish politician told Reuters on Sunday, expressing hope for a deal that would halt a Turkish attack. Ahmed Suleiman, a senior member of the Kurdish Democratic Progressive Party in Syria, said the talks were being held at Russia's Hmeimim airbase in Latakia. He did not say if he or his party - which is independent from the SDF - had a role in the negotiations. Asked about Suleiman's comments, the head of the SDF media...