fix: 清单指引显示bug

web/maintain/billsGuidance_lib/js/billsGuidance.js

@@ -418,8 +418,8 @@ const billsGuidance = (function () {
                 } else {
                     sheet.setCellType(row, 1, baseType);
                     sheet.setCellType(row, 2, baseType);
-                    sheet.setValue(row, 1, null);
-                    sheet.setValue(row, 2, null);
+                    sheet.setValue(row, 1, '');
+                    sheet.setValue(row, 2, '');
                 }
             })
         });