[Fix] Restore multiple values headers in protocol
[Fix] Restore multiple values headers in protocol

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