Stop checking diffs.txt
Stop checking diffs.txt

It means "make check_utf8" takes twice as long and it's redundant with
checking that the output matches output.txt.

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