By Stephanie Nebehay GENEVA (Reuters) -More than 100 diplomats from some 40 Western countries and allies including Japan walked out of a speech by Russian Foreign Minister Sergei Lavrov to the top U.N. human rights forum on Tuesday in protest over Russia’s invasion of Ukraine. The boycott by envoys from the European Union, the United States, Britain and others left only a few diplomats in the room including Russia’s ambassador to the U.N. in Geneva, Gennady Gatilov, who is a former deputy to Lavrov. Envoys from Syria, China and Venezuela were among delegations that stayed. Lavrov was addressin…