fix: lineno typo
@@ -123,7 +123,7 @@ name = "functions4"
path = "exercises/functions/functions4.rs"
mode = "compile"
hint = """
-The error message points to line 14 and says it expects a type after the
+The error message points to line 17 and says it expects a type after the
`->`. This is where the function's return type should be -- take a look at
the `is_even` function for an example!
