British Prime Minister Boris Johnson on Saturday urged the EU to use the two sides’ newfound spirit of cooperation over Ukraine to unblock tortured talks about post-Brexit trade in Northern Ireland. At a meeting in London with Irish premier Micheal Martin, Johnson said that Brussels still needed to make “significant changes” to the so-calledNorthern Ireland Protocol, according to a Downing Street statement. The UK and the EU negotiated the Northern Ireland Protocol as part of the Brexit withdrawal agreement. Pro-UK unionists have collapsed the divided province’s devolved government, and insist…