Update app.py

app.py

@@ -16,7 +16,7 @@ def sum_of_two_number(num1:int, num2:int)-> int: #it's import to specify the ret
         num1: the first number (e.g., 12)
         num2: the second number (e.g., -76)
     """
-        sum = num1 + num2
+    sum = num1 + num2
     
     return sum