avm2: Fix null parameter error message

Author: Herschel

core/src/avm2/parameters.rs

@@ -174,7 +174,7 @@ impl<'gc> ParametersExt<'gc> for &[Value<'gc>] {
 pub fn null_parameter_error<'gc>(activation: &mut Activation<'_, 'gc>, name: &str) -> Error<'gc> {
     let error = type_error(
         activation,
-        &format!("Parameter {name} must be non-null."),
+        &format!("Error #2007: Parameter {name} must be non-null."),
         2007,
     );
     match error {