Update app.py

app.py

@@ -50,7 +50,7 @@ def check_is_prime(number_to_check:int)-> str: #it's import to specify the retur
             # If num is divisible by any number between
             # 2 and n / 2, it is not prime
             if (number_to_check % i) == 0:
-                return_text = "is not a prime number")
+                return_text = "is not a prime number"
                 break
         else:
             return_text = "is a prime number"