[mongo] Fix case where optimeDate is not available
[mongo] Fix case where optimeDate is not available


Fix #2581
jyogi/purvar-agent,jyogi/purvar-agent,Wattpad/dd-agent,jyogi/purvar-agent,indeedops/dd-agent,manolama/dd-agent,indeedops/dd-agent,jyogi/purvar-agent,manolama/dd-agent,indeedops/dd-agent,Wattpad/dd-agent,manolama/dd-agent,cberry777/dd-agent,takus/dd-agent,takus/dd-agent,cberry777/dd-agent,Wattpad/dd-agent,takus/dd-agent,cberry777/dd-agent,Wattpad/dd-agent,Wattpad/dd-agent,takus/dd-agent,manolama/dd-agent,cberry777/dd-agent,indeedops/dd-agent,jyogi/purvar-agent,indeedops/dd-agent,manolama/dd-agent,takus/dd-agent,cberry777/dd-agent