rename ldap service map

since we drop /etc/pam.d/dovecot the service name sent from pam is 'dovecot',
also nginx-mail-mapper has been integrated into authserv now.

debian/ai-auth-server.conf

@@ -9,8 +9,8 @@ host = socket.gethostname().split('.')[0]
 
 LDAP_SERVICE_MAP = {
 
-    # Mail accounts (dovecot, nginx-mail-mapper).
-    'mail': {
+    # Mail accounts (dovecot).
+    'dovecot': {
         'base': 'ou=People, dc=investici, dc=org, o=Anarchy',
         'filter': '(&(objectClass=virtualMailUser)(status=active)(mail=%(user)s))',
     },