Don't call certificate-related functions when not checking certificates

I want to make an app that calls an api in `http://localhost/`, so it doesn't make too much sense to use certificates.
So, because of [this bug in hs-certificate](https://github.com/vincenthz/hs-certificate/issues/92) I decided to disable them following the instructions mentioned in issue #102, but the program still spends most of its time on functions from `Data.X509.CertificateStore`, acording to the profiling report.

So, maybe the library could realize I'm not using https and just avoid calling those functions?