Revert "Update app.py"

This reverts commit a210bcd13c127315db7457c4bc31c5df4b039696.

app.py

@@ -218,7 +218,7 @@ with gr.Blocks(css="#chatbot {overflow:auto; height:500px;} .message img {max-wi
     run.click(bot.run_text, [txt, state], [chatbot, state])
     run.click(lambda: "", None, txt)
 
-    def refer_to_image(evt, text):
+    def refer_to_image(evt: gr.SelectData, text):
         result = re.search(r"image\/\S+\.png", evt.value)
         if result:
             text = text + " " + result.group() + " "