Fixed missing return in Service::loadById.

core/service.h

@@ -45,8 +45,9 @@ public:
     QSharedPointer<T> loadById(int id) {
         odb::database *db = Context::instance().db();
         odb::transaction tx(db->begin());
-        db->template load<T>(id);
+        QSharedPointer<T> entity = db->template load<T>(id);
         tx.commit();
+        return entity;
     }
 };