main/cdr: Use 'time' when rescheduling batched CDRs as opposed to 'size'

When refactoring CDRs to use the configuration framework, a 'whoops' was
introduced where the CDR batch size was used when rescheduling a batch,
as opposed to the time duration. This patch corrects that obvious mistake.

ASTERISK-24426 #close
Reported by: Shane Blaser
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Merged revisions 425735 from http://svn.asterisk.org/svn/asterisk/branches/12
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Merged revisions 425736 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@425744 65c4cc65-6c06-0410-ace0-fbb531ad65f3