GnuTLS is not built with openssl compatibility by default

[daveti]

As a result, the build would complain gnutls/openssl.h no such file, even if the gnutls-devel has been installed. A quick workaround is to change the USE_GNUTLS to no in the Makefile. My only concern is if there is a reason to stick with GnuTLS and its compatible openssl lib.

BTW, the commit from gnutls to remove openssl by default:
https://gitlab.com/gnutls/gnutls/commit/4aa59d7daa95f7ee40dfeb61fdfa331a1d33eb63

Thanks,
Dave