pkg/morph: make read network's magic uint32

When I wanted to use it, I wrote all the code based on `uint32` (because I knew
it should be this way), and at the last moment I found that `client` package
returns it as `uint64` for no reason.

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

cmd/neofs-node/netmap.go

@@ -388,7 +388,7 @@ type netInfo struct {
 	netState netmap.State
 
 	magic interface {
-		MagicNumber() (uint64, error)
+		MagicNumber() (uint32, error)
 	}
 
 	morphClientNetMap *nmClient.Client
@@ -404,7 +404,7 @@ func (n *netInfo) Dump(ver version.Version) (*netmapSDK.NetworkInfo, error) {
 
 	var ni netmapSDK.NetworkInfo
 	ni.SetCurrentEpoch(n.netState.CurrentEpoch())
-	ni.SetMagicNumber(magic)
+	ni.SetMagicNumber(uint64(magic))
 
 	netInfoMorph, err := n.morphClientNetMap.ReadNetworkConfiguration()
 	if err != nil {

pkg/morph/client/client.go

@@ -533,15 +533,15 @@ func (c *Client) roleList(r noderoles.Role) (keys.PublicKeys, error) {
 
 // MagicNumber returns the magic number of the network
 // to which the underlying RPC node client is connected.
-func (c *Client) MagicNumber() (uint64, error) {
+func (c *Client) MagicNumber() (uint32, error) {
 	c.switchLock.RLock()
 	defer c.switchLock.RUnlock()
 
 	if c.inactive {
 		return 0, ErrConnectionLost
 	}
 
-	return uint64(c.rpcActor.GetNetwork()), nil
+	return uint32(c.rpcActor.GetNetwork()), nil
 }
 
 // BlockCount returns block count of the network