fix(backend): fix model list api error if not init model info from config (#250)

Co-authored-by: sibianl <sibianl@rings.net.cn>

Author: sl-gn

src/backend/server/static_config.py

@@ -173,6 +173,8 @@ def init_model_info_dict_cache(use_hfcache: bool = False):
 
 
 def get_model_info_dict_cache():
+    if model_info_dict_cache is None:
+        return {}
     return model_info_dict_cache