Update app.py

Trying to include the import statement in the app.py code

app.py

@@ -13,6 +13,9 @@ import json
 
 from tools.visit_webpage import VisitWebpageTool
 
+# Trying to fix an error I was getting:
+import re
+
 # Below is an example of a tool that does nothing. Amaze us with your creativity !
 @tool
 def my_custom_tool(arg1:str, arg2:int)-> str: #it's import to specify the return type