Adjusting permission on l10n.mozilla.org to reflect sign-off policies

Hi,

this is a quick reminder that a looong time back, we've changed 
sign-offs to be done by the l10n project managers.

What we haven't done is to actually update the permissions on 
l10n.mozilla.org to reflect that. We're doing that now.

We also stopped requiring release folks to access l10n.mozilla.org, so 
we're dropping that access logic, too.

This shouldn't impact anything that anybody's doing, but if it does, 
ping me.

Axel