[FIX] failure to switch view due to switching to a non-existant view should not crash the viewmanager anymore
[FIX] failure to switch view due to switching to a non-existant view should not crash the viewmanager anymore

havt/openerp-web,havt/openerp-web,akretion/openerp-web,havt/openerp-web,akretion/openerp-web,havt/openerp-web,akretion/openerp-web,havt/openerp-web