better detection of empty database

src/main/java/com/commafeed/backend/dao/UserDAO.java

@@ -28,4 +28,8 @@ public class UserDAO extends GenericDAO<User> {
 		return newQuery().from(user).where(user.email.equalsIgnoreCase(email)).leftJoin(user.roles, QUserRole.userRole).fetch()
 				.uniqueResult(user);
 	}
+
+	public long count() {
+		return newQuery().from(user).count();
+	}
 }

src/main/java/com/commafeed/backend/service/StartupService.java

@@ -48,7 +48,7 @@ public class StartupService implements Managed {
 		new UnitOfWork<Void>(sessionFactory) {
 			@Override
 			protected Void runInSession() throws Exception {
-				if (userDAO.findByName(CommaFeedApplication.USERNAME_ADMIN) == null) {
+				if (userDAO.count() == 0) {
 					initialData();
 				}
 				return null;