Fix typo in app.py

app.py

@@ -8,7 +8,7 @@ from tools.final_answer import FinalAnswerTool
 from Gradio_UI import GradioUI
 
 @tool
-def my_cutom_tool(arg1:str, arg2:int)-> str: #it's import to specify the return type
+def my_custom_tool(arg1:str, arg2:int)-> str: #it's import to specify the return type
     #Keep this format for the description / args / args description but feel free to modify the tool
     """A tool that does nothing yet 
     Args: