Update Validator.java

dotCMS doest support emails with a local part(before the @) of more than 24.

However, the RFC states the local part may be 64 characters.

We have clients who's email are greater than 24 characters

```
The format of email addresses is local-part@domain where the local-part may be up to 64 characters long and the domain name may have a maximum of 253 characters – but the maximum of 256-character length of a forward or reverse path restricts the entire email address to be no more than 254 characters long.[2] The formal definitions are in RFC 5322 and RFC 5321 - Wikipedia
```