xdr: update using xdrgen#73 (#4073)

Author: 2opremio

Diff for: Gemfile.lock

@@ -1,6 +1,6 @@
 GIT
   remote: https://github.com/stellar/xdrgen.git
-  revision: 0e66fb9029643d3e59b381c01c446782a49c26fe
+  revision: b960ce7a979bc64d11f7512962733ee88ea87a2b
   ref: master
   specs:
     xdrgen (0.1.1)

Diff for: xdr/xdr_generated.go

@@ -1270,9 +1270,9 @@ var _ xdrType = (*DataValue)(nil)
 type PoolId Hash
 
 // EncodeTo encodes this value using the Encoder.
-func (s PoolId) EncodeTo(e *xdr.Encoder) error {
+func (s *PoolId) EncodeTo(e *xdr.Encoder) error {
 	var err error
-	if err = (*Hash)(&s).EncodeTo(e); err != nil {
+	if err = (*Hash)(s).EncodeTo(e); err != nil {
 		return err
 	}
 	return nil