FRANKFURT (Reuters) – The online-only consumer banking division of Russia’s VTB in Europe has turned off its phones due to high call volume and is asking customers to email instead, according to a notice on its website on Monday. Reuters reported last week that regulators are preparing for a possible closure of the European arm of Russia’s second-largest bank amid growing concerns about the impact on it of Western sanctions following the Ukraine invasion. The German regulator BaFin has banned the bank from taking new customers, and VTB has sought to reassure customers that it is stable and ful…