解析excel表格时，当一行为null时自动跳过

src/main/java/com/wangxiaolu/promotion/common/excel/ReadExcelUtils.java

@@ -94,6 +94,9 @@ public class ReadExcelUtils {
         // 正文内容应该从第二行开始,第一行为表头的标题
         for (int i = 1; i <= rowNum; i++) {
             row = sheet.getRow(i);
+            if (row == null) {
+                continue;
+            }
             int j = 0;
 
             List<Object> cellValues = new ArrayList<>(rowNum * 2);