fixed nil check on nodes in DKG (#54)

share/dkg/dkg.go

@@ -192,7 +192,7 @@ type DistKeyGenerator struct {
 // NewDistKeyHandler takes a Config and returns a DistKeyGenerator that is able
 // to drive the DKG or resharing protocol.
 func NewDistKeyHandler(c *Config) (*DistKeyGenerator, error) {
-	if c.NewNodes == nil && c.OldNodes == nil {
+	if len(c.NewNodes) == 0 && len(c.OldNodes) == 0 {
 		return nil, errors.New("dkg: can't run with empty node list")
 	}
 	if len(c.Nonce) != NonceLength {
@@ -207,7 +207,7 @@ func NewDistKeyHandler(c *Config) (*DistKeyGenerator, error) {
 		isResharing = true
 	}
 	if isResharing {
-		if c.OldNodes == nil {
+		if len(c.OldNodes) == 0 {
 			return nil, errors.New("dkg: resharing config needs old nodes list")
 		}
 		if c.OldThreshold == 0 {