!488 修复操作日志列表查询业务类型时的bug

ruoyi-system/src/main/resources/mapper/system/SysOperLogMapper.xml

@@ -39,7 +39,7 @@ PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
 			<if test="title != null and title != ''">
 				AND title like concat('%', #{title}, '%')
 			</if>
-			<if test="businessType != null and businessType != ''">
+			<if test="businessType != null">
 				AND business_type = #{businessType}
 			</if>
 			<if test="businessTypes != null and businessTypes.length > 0">