[to #42322933]fix image_open func, support url

Link: https://code.alibaba-inc.com/Ali-MaaS/MaaS-lib/codereview/10548014

    * fix image_open func

modelscope/preprocessors/multi_modal.py

@@ -157,7 +157,7 @@ class MPlugPreprocessor(Preprocessor):
     def image_open(self, path: str) -> Tuple[Image.Image, int]:
         if path not in self._image_map:
             index = len(self._image_map)
-            self._image_map[path] = (Image.open(path), index)
+            self._image_map[path] = (load_image(path), index)
         return self._image_map[path]
 
     def __call__(