Fix setting the info.yaml inform field when email is known

In the Ntupling Service, the email is set automatically through the user logging in. The function that creates the info.yaml file was not yet adjusted to this specific use case, leaving the inform field inside info.yaml empty sometimes.

This MR fixes the issue by checking whether the email is already known; if so, it retrieves the email from localStorage. If not, the wizard's behaviour remains the same.