node/object/replicate_test: fix replication signature test

An omission from ae6e37d: check all 3
signatures and slice them correctly.

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

pkg/network/transport/object/grpc/replication_test.go

@@ -398,7 +398,7 @@ func TestServer_Replicate(t *testing.T) {
 
 			sigsRaw := resp.GetObjectSignature()
 
-			for i := range 1 {
+			for i := range 3 {
 				var sigV2 refsv2.Signature
 				l := binary.LittleEndian.Uint32(sigsRaw)
 
@@ -410,9 +410,9 @@ func TestServer_Replicate(t *testing.T) {
 				require.Equal(t, signer.PublicKeyBytes, sig.PublicKeyBytes())
 				require.True(t, sig.Verify(objectcore.EncodeReplicationMetaInfo(
 					o.GetContainerID(), o.GetID(), o.GetFirstID(), o.GetPreviousID(), o.PayloadSize(), o.Type(), nil, nil,
-					uint64((123+1+i)*240), mNumber)))
+					uint64((123+1+i)*240), mNumber)), i)
 
-				sigsRaw = sigsRaw[:4+l]
+				sigsRaw = sigsRaw[4+l:]
 			}
 		})
 	})