[views] fix wrong message in registration box (closes #1765191)

views.py

@@ -78,9 +78,10 @@ class ConferenceRegistrationComponent(component.CtxComponent):
             if reg_open:
                 self.label = register_now
         else:
-            has_cart = self._cw.execute('Any C WHERE U eid %(x)s, C buyer U', {'x': self._cw.user.eid})
-            items = self._cw.execute('Any I WHERE U eid %(x)s, C buyer U, C items_in_cart I',
-                                     {'x': self._cw.user.eid})
+            has_cart = self._cw.execute('Any SC WHERE U eid %(x)s, SC buyer U', {'x': self._cw.user.eid})
+            items = self._cw.execute('Any I WHERE U eid %(u)s, SC buyer U, SC items_in_cart I, '
+                                     'I item_type T, C has_shoppingitemtype T, C eid %(c)s',
+                                     {'u': self._cw.user.eid, 'c': self.conf.eid})
             if has_cart:
                 if items:
                     state = has_cart.get_entity(0, 0).cw_adapt_to('IWorkflowable').state