scripts-remove shouldn't sign users up for sql.mit.edu

[adehnert]

As far as I can tell, scripts-remove will sign users up for sql.mit.edu if they haven't been already. This seems poor. (I believe that it should be reasonable to be running scripts-remove without having been signed up for sql.mit.edu --- phpical, for example, has a line "requires_sql=0" that I assume suppresses signing up for sql.mit.edu).

In particular:

• scripts-remove unconditionally uses sshrun to execute get-password
• get-password appears to run sql-signup if the account doesn't exist already

To make matters worse, it appears that the process doesn't actually write the new credentials into the locker anywhere, which I believe can cause problems elsewhere.