cmake HAVE_GNUTLS_TRANSPORT_IS_KTLS_ENABLED examples

sahlberg/libnfs cmake/ConfigureChecks.cmake :83

check_c_source_compiles("#include <gnutls/socket.h>
                         int main()
                         {
                                gnutls_session_t session;
                                gnutls_transport_is_ktls_enabled(session);
                         }"
                        HAVE_GNUTLS_TRANSPORT_IS_KTLS_ENABLED)