By Guy Faulconbridge and Felix Light LONDON (Reuters) -The withdrawal of Russian forces from a strategically important town in eastern Ukraine has prompted two powerful allies of President Vladimir Putin to do something rare in modern Russia: publicly ridicule the war machine’s top brass. Russia’s loss of the bastion of Lyman, which puts western parts of Luhansk region under threat, touched a nerve for Ramzan Kadyrov, the leader of the southern Russian republic of Chechnya. Kadyrov, who has been close to Putin since his father and former president of Chechnya, Akhmad, was killed in a 2004 bomb…