How to remove ca certificate notification

[Vishal2900]

I don't know how to describe it but ... this what happened..
1 installed Facebook research ...given all the permission...but after few hours I noticed it's draining my battery...so I uninstalled
2 after uninstalling I can still see this notification ... attached screenshot...
How to remove those..

 

[VDG]

Just remove CA certificate from settings>>Security

 

[sk679558]

what is this CA certification man explain pls