Ukraine’s ambassador to Germany did not take part in a concert in solidarity with Ukraine organized by his host government on Sunday because no Ukrainian soloists were billed to play. “Only Russian soloists, no Ukrainians,” Andriy Melnyk tweeted, along with what appeared to be a screenshot of the invitation. “An affront. Sorry, I’m staying away.” German President Frank-Walter Steinmeier opened the Berliner Philharmonker concert via videolink, having caught the coronavirus. According to Steinmeier’s office, musicians from Ukraine, Russia, Belarus and Germany, among others, were to perform piece…