message: Print proper error message when running wasmer login
diff: @@ -53,7 +53,7 @@ impl Login {
  let token = self.get_token_or_ask_user()?;
  match wasmer_registry::login::login_and_save_token(&self.registry, &token)? {
  Some(s) => println!("Login for WAPM user {:?} saved", s),
  - None => println!("Login for WAPM user saved"),
  + None => println!("Error: no user found on registry {:?} with token {:?}. Token saved regardless.", self.registry, token),
  }
  Ok(())
  }
  