Use POD_ADDRESS_RANGE for Dovecot if it exists

This is required to override allow_nets in a Kubernetes environment where pods are not recreated with the same IP address.

core/dovecot/conf/dovecot-sql.conf.ext

@@ -3,7 +3,7 @@ connect = /data/main.db
 
 # Return the user hashed password
 password_query = \
- SELECT NULL as password, 'Y' as nopassword, '{{ FRONT_ADDRESS }}{% if WEBMAIL_ADDRESS %},{{ WEBMAIL_ADDRESS }}{% endif %}' as allow_nets \
+ SELECT NULL as password, 'Y' as nopassword, '{% if POD_ADDRESS_RANGE %}{{ POD_ADDRESS_RANGE }}{% else %}{{ FRONT_ADDRESS }}{% if WEBMAIL_ADDRESS %},{{ WEBMAIL_ADDRESS }}{% endif %}{% endif %}' as allow_nets \
    FROM user \
   WHERE user.email = '%u'