fix: 过滤空白的sheet

--bug=1049943 --user=刘瑞斌 【文档内容提取】-上传的excel中sheet为空时报错 https://www.tapd.cn/57709429/s/1625062

Author: liuruibin

apps/common/handle/impl/table/xlsx_parse_table_handle.py

@@ -90,7 +90,8 @@ def get_content(self, file, save_image):
             for sheetname in workbook.sheetnames:
                 sheet = workbook[sheetname] if sheetname else workbook.active
                 rows = self.fill_merged_cells(sheet, image_dict)
-
+                if len(rows) == 0:
+                    continue
                 # 提取表头和内容
 
                 headers = [f"{key}" for key, value in rows[0].items()]