Poland’s ski jumpers were deal another pre-Olympics blow on Friday when former Four Hills Tournament winner Dawid Kubacki tested positive for the coronavirus. The 31-year-old Kubacki will miss his home World Cup competitions in Zakopane this weekend, as will triple Olympic champion Kamil Stoch who has an ankle injury. Kubacki, and team-mate Pawel Wasek who also tested positive, has enough time to recover before the February 4 start of the Winter Games in Beijing but must test negative to be permitted into China. The Polish team has had a bitterly disappointing season so far with Stoch 16th in …