By Kate Abnett and Jan Strupczewski BRUSSELS (Reuters) -EU countries scrambled on Friday to reach a deal that would embargo seaborne deliveries of Russian oil but still allow deliveries by pipeline, a compromise to win over Hungary and unblock new sanctions against Moscow, officials said. An agreement could be reached by envoys of European Union governments in Brussels on Sunday, in time for their leaders to endorse it at their May 30-31 summit, officials said, noting the urgency after almost a month of negotiations had failed. Hungary has held up the EU’s sixth package of sanctions against Ru…