added another cipher mapping for openvpn tests

crypto/cipher_extra/cipher_extra.c

@@ -105,6 +105,7 @@ static const struct {
     {"aes256", "aes-256-cbc"},
     {"aes128", "aes-128-cbc"},
     {"id-aes128-gcm", "aes-128-gcm"},
+    {"id-aes192-gcm", "aes-192-gcm"},
     {"id-aes256-gcm", "aes-256-gcm"}
 };