[TT-3692] track: deleting a security policy doesn't revoke access for the key

[asoorm]

https://tyktech.atlassian.net/browse/TT-1297

Workaround is to create a dummy policy, then delete it again. Which triggers the Gateway to reload it's internal policy representation.

Should we do this inside the Operator till issue is fixed?

FYI @gernest