Fix comment typo
Fix comment typo

Reported by Veres Lajos via Xapian.

snowballstem/snowball,snowballstem/snowball,JDemler/snowball,assem-ch/snowball,cesarsouza/snowball,xjzhou/snowball,assem-ch/snowball,kariminf/snowball,cesarsouza/snowball,JDemler/snowball,goodotcom/snowball,omron93/snowball,goodotcom/snowball,cesarsouza/snowball,kariminf/snowball,kariminf/snowball,omron93/snowball,cesarsouza/snowball,snowballstem/snowball,xjzhou/snowball,goodotcom/snowball,assem-ch/snowball,kariminf/snowball,assem-ch/snowball,snowballstem/snowball,snowballstem/snowball,kariminf/snowball,cesarsouza/snowball,snowballstem/snowball,JDemler/snowball,xjzhou/snowball,assem-ch/snowball,xjzhou/snowball,JDemler/snowball,JDemler/snowball,cesarsouza/snowball,goodotcom/snowball,JDemler/snowball,omron93/snowball,snowballstem/snowball,cesarsouza/snowball,xjzhou/snowball,snowballstem/snowball