Wrong error message for PasswordTooLong error

[josecelano]

Reported in: torrust/torrust-index-gui#613

pub enum ServiceError {
    #[display(fmt = "internal server error")]
    InternalServerError,

    // ...

    #[display(fmt = "Password too short")]
    PasswordTooShort,
    #[display(fmt = "Username too long")]
    PasswordTooLong,
    #[display(fmt = "Passwords don't match")]
    PasswordsDontMatch,

    // ...

It should be:

pub enum ServiceError {
    #[display(fmt = "internal server error")]
    InternalServerError,

    // ...

    #[display(fmt = "Password too short")]
    PasswordTooShort,
    #[display(fmt = "Password too long")]
    PasswordTooLong,
    #[display(fmt = "Passwords don't match")]
    PasswordsDontMatch,

    // ...