[Fix] Milter headers: skip_local / skip_authenticated settings
[Fix] Milter headers: skip_local / skip_authenticated settings

 - Fixes: #1850
 - Reported by: @iflyhigh
 - MFH: rspamd-1.6

AlexeySa/rspamd,AlexeySa/rspamd,AlexeySa/rspamd,AlexeySa/rspamd,AlexeySa/rspamd,AlexeySa/rspamd,AlexeySa/rspamd,AlexeySa/rspamd,AlexeySa/rspamd