cdr_adaptive_odbc: Also apply a filter when the CDR value is empty.

Extra CDR records are written if a filtered CDR value is empty because the
filter is not checked.

(closes issue ASTERISK-22272)
Reported by: Jordi Llull Chavarria
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Merged revisions 401577 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 401579 from http://svn.asterisk.org/svn/asterisk/branches/11
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Merged revisions 401581 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@401582 65c4cc65-6c06-0410-ace0-fbb531ad65f3