fix：优化上传图片组件数量限制

lib/upload_image/upload_images_tool.dart

@@ -26,7 +26,7 @@ class UploadImagesTool {
   }) async {
     await chooseCamera(
       context: context,
-      max: max,
+      max: max??9,
       oSSAccessKeyId: oSSAccessKeyId ?? '',
       ossHost: ossHost ?? '',
       ossDirectory: ossDirectory ?? '',