fix：

分页查询排序bug修复

tr-plugins/tr-spring-boot-starter-plugin-mybatis/src/main/java/cn/tr/plugin/mybatis/config/page/PageConfig.java

@@ -30,7 +30,7 @@ public class PageConfig {
             Integer size = pageDomain.getSize();
             Page<Object> page = PageHelper.startPage(current, size).setReasonable(true);
             String orderBy = parseOrders(pageDomain.getOrders());
-            if(StrUtil.isNotEmpty(orderBy)){
+            if(StrUtil.isNotBlank(orderBy)){
                 page.setOrderBy(orderBy);
             }
             PageContextHolder.setPage(page);
@@ -49,6 +49,9 @@ public class PageConfig {
         for (int i = 0; i < orders.size(); i++) {
             Order order = orders.get(i);
             String field = order.getField();
+            if(StrUtil.isBlank(field)){
+                continue;
+            }
             Direction direction = order.getDirection();
             result.append(StrUtil.toUnderlineCase(field));
             result.append(" ");