Update app.py

app.py

@@ -31,7 +31,7 @@ def respond(
         req = models.ChatCompletionsRequest()
 
         for val in history:
-            if val[0] andval[1]:
+            if val[0] and val[1]:
                 messages.append({"Role": "user", "Content": val[0]})
                 messages.append({"Role": "assistant", "Content": val[1]})