TLS: disable by default cipher suites using RSA key exchange

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

internal/util/util.go

@@ -71,7 +71,6 @@ var (
 		tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
 		tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
 		tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256, tls.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
-		tls.TLS_RSA_WITH_AES_128_GCM_SHA256, tls.TLS_RSA_WITH_AES_256_GCM_SHA384,
 	}
 )