Julen Lopetegui has a clause inserted into his contract as West Ham conceal the length of his deal as Hammers boss. West Ham finally officially unveiled Julen Lopetegui on Thursday morning, two weeks after he signed on the dotted line. The Hammers held off on confirmation until after David Moyes and his staff had seen the season out and departed. Moyes was spotted for the first time in public this week since clearing out his office at West Ham. And 57-year-old former Spain boss Lopetegui was formally introduced as his successor on Thursday morning. Lopetegui becomes West Ham’s 18th permanent b…