Use raw mode on custom or broken sieve file (#3387)

* Use raw mode on custom or broken sieve file

* Fixed display of sieve filters when none are active

* Updated test

docker/dovecot_config/auth-custom.conf

@@ -5,6 +5,10 @@ auth_debug = yes
 auth_verbose = yes
 auth_debug_passwords = yes
 
+# Disabling SSL (dev)
+ssl=no
+disable_plaintext_auth=no
+
 passdb {
   driver = oauth2
   mechanisms = xoauth2 oauthbearer