By Ben Aris in Berlin Hungarian Prime Minister Viktor Orban posted a picture on social media of himself arriving at Moscow’s airport with the caption: “peace mission continues, second stop – Moscow.” The visit by Orban, seen as one of Putin’s staunchest allies in Europe, is the first by an EU leader to Russia since Austrian Chancellor Karl Nehammer’s failed attempt to end the war in April 2022. It was slammed by top EU officials including recently appointed EU foreign policy chief Kaja Kallas. ‘I am grateful to you that you agreed to receive me even in such challenging conditions,’ the Hungari…