BUG/MINOR: acl: acl parser does not recognize empty converter list

Commit 348971e (MEDIUM: acl: use the fetch syntax 'fetch(args),conv(),conv()'
into the ACL keyword) introduced a regression in the ACL parser. The second
argument of an ACL keyword is now mistakenly confused with a converter.

This bug is post-dev19 and does not require any backport.
1 file changed