Allow ` ' ` (single quotes) in SSL certificate names.

Do not allow `"` (double quotes) though, as that is just....

Raise a Validation Error in the create internal certificate form,
when a `"` is entered in the certificate name.

Thanks to Dr. KK for this (he practically fixed it!, I just commited).

Ticket: #6538
Let Apache and Nginx use certs with spaces and single quotes in them.