[Minor] Use byte array not gstring for input buffer
[Minor] Use byte array not gstring for input buffer

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