fix shipfee not find

@@ -98,7 +98,9 @@
     SELECT DISTINCT cpn.id FROM coupon cpn
     LEFT JOIN `coupon_product_limit` cpl ON cpl.`coupon_id` = cpn.id
     WHERE   coupon_type = #{couponType}
+    <if test="useLimitType != null">
       and use_limit_type =  #{useLimitType}
+    </if>
     and ((cpn.`product_limit_type` = 1 AND cpl.`product_id` = #{productId}) OR (cpn.`product_limit_type` = 3 AND cpl.`product_id` != #{productId}) OR cpn.`product_limit_type` =2)
   </sql>