Fix wrong required state on Move.currency

move.py

@@ -101,7 +101,7 @@ class Move(ModelSQL, ModelView):
     currency = fields.Many2One('currency.currency', 'Currency',
         states={
             'invisible': Not(Bool(Eval('unit_price_required'))),
-            'required': Not(Bool(Eval('unit_price_required'))),
+            'required': Bool(Eval('unit_price_required')),
             'readonly': Not(Equal(Eval('state'), 'draft')),
             },
         depends=['unit_price_required', 'state'])