修复日志列表取消字段排序时的报错问题

src/main/java/com/ruoyi/framework/web/page/PageDomain.java

@@ -67,15 +67,18 @@ public class PageDomain
 
     public void setIsAsc(String isAsc)
     {
-        // 兼容前端排序类型
+        if (StringUtils.isNotEmpty(isAsc))
-        if ("ascending".equals(isAsc))
         {
-            isAsc = "asc";
+            // 兼容前端排序类型
+            if ("ascending".equals(isAsc))
+            {
+                isAsc = "asc";
+            }
+            else if ("descending".equals(isAsc))
+            {
+                isAsc = "desc";
+            }
+            this.isAsc = isAsc;
         }
-        else if ("descending".equals(isAsc))
-        {
-            isAsc = "desc";
-        }
-        this.isAsc = isAsc;
     }
 }