add model cache and fix font

app.py

@@ -68,7 +68,7 @@ def change_model_name(name):
 
 
 def predict(model_name, text):
-    if model_name != MODEL_NAME:
+    if model_name != MODEL_BUF["name"]:
         change_model_name(model_name)
     
     tokenizer = MODEL_BUF["tokenizer"]