[Fix] Unbreak build on gcc < 4.9
[Fix] Unbreak build on gcc < 4.9

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