fixed up the checks to support pymongo 1.8+
fixed up the checks to support pymongo 1.8+

hdeheer/nagios-plugin-mongodb,Elbandi/nagios-plugin-mongodb,cookbooks/nd-nagios-plugin-mongodb,MingjunZhao/Mapscape-Nagios-Mongo,adrianlzt/nagios-plugin-mongodb,warrenpnz/nagios-plugin-mongodb,alexp789/nagios-plugin-mongodb,a-yiorgos/nagios-plugin-mongodb,mzupan/nagios-plugin-mongodb