RPC: Introduce virNetStreamHole

This is going to be RPC representation for virStreamSendHole.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

src/rpc/virnetprotocol.x

@@ -236,3 +236,8 @@ struct virNetMessageError {
     int int2;
     virNetMessageNetwork net; /* unused */
 };
+
+struct virNetStreamHole {
+    hyper length;
+    unsigned int flags;
+};

src/virnetprotocol-structs

@@ -42,3 +42,7 @@ struct virNetMessageError {
         int                        int2;
         virNetMessageNetwork       net;
 };
+struct virNetStreamHole {
+        int64_t                    length;
+        u_int                      flags;
+};