Update SmsCouponServiceImpl.java

mall-admin/src/main/java/com/macro/mall/service/impl/SmsCouponServiceImpl.java

@@ -13,7 +13,6 @@ import com.macro.mall.model.*;
 import com.macro.mall.service.SmsCouponService;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
-import org.springframework.util.StringUtils;
 
 import java.util.List;