Do not define rattail mail templates by default

pretty sure that value was/is already fallback default anyway

rattail_fabric2/deploy/rattail/rattail.conf.mako

@@ -19,7 +19,6 @@ configure_logging = true
 
 [rattail.mail]
 smtp.server = localhost
-templates = rattail:templates/mail
 default.from = ${getattr(env, 'email_default_sender', 'rattail@localhost')}
 default.to = ${', '.join(getattr(env, 'email_default_recipients', ['root@localhost']))}