image: sk-packet -- Reserve fields

To handle message addresses and ucreds.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

images/sk-packet.proto

@@ -8,5 +8,9 @@ message scm_entry {
 message sk_packet_entry {
 	required uint32		id_for		= 1;
 	required uint32		length		= 2;
+	// Reserved for message address
+	// optional bytes		addr	= 3;
 	repeated scm_entry	scm		= 4;
+	// Reserved for ucred restore
+	// optional sk_ucred_entry	ucred	= 128;
 }