fixes

app.py

@@ -110,7 +110,8 @@ def set_chain_up(api_key, model_selector, k_textbox, agent):
             model_selector = "gpt-3.5-turbo"
         if not k_textbox:
             k_textbox = 10
-        k_textbox = int(k_textbox)
+        else:
+            k_textbox = int(k_textbox)
         qa_chain = get_new_chain1(vectorstore, model_selector, k_textbox)
         os.environ["OPENAI_API_KEY"] = ""
         return qa_chain