bug 2827: sometimes there is a "Argument "" isn't numeric in numeric lt (<)" warning that gets printed from the Bayes code.  it turns out that where the DB module ought to be returning undef, it sometimes returns "", so add a check for that possibility.
bug 2827: sometimes there is a "Argument "" isn't numeric in numeric lt
(<)" warning that gets printed from the Bayes code.  it turns out that
where the DB module ought to be returning undef, it sometimes returns
"", so add a check for that possibility.



git-svn-id: d99324e817494df82bb0080d8e7ab74680731a10@6080 13f79535-47bb-0310-9956-ffa450edef68

apache/spamassassin,apache/spamassassin,apache/spamassassin,apache/spamassassin,apache/spamassassin