message: Remove misleading hint from error message
diff: @@ -135,7 +135,7 @@ fn check_wasm_exports(module: &Module) -> VmResult<()> {
  for required_export in REQUIRED_EXPORTS {
  if !available_exports.contains(*required_export) {
  return Err(VmError::static_validation_err(format!(
  - "Wasm contract doesn't have required export: \"{}\". Exports required by VM: {:?}. Contract version too old for this VM?",
  + "Wasm contract doesn't have required export: \"{}\". Exports required by VM: {:?}.",
  required_export, REQUIRED_EXPORTS
  )));
  }
  