Merge pull request #6239 from volzhs/fix-return-spb

Fix StreamPeerBuffer::duplicate() does not return value

core/io/stream_peer.cpp

@@ -544,6 +544,7 @@ Ref<StreamPeerBuffer> StreamPeerBuffer::duplicate() const {
 	Ref<StreamPeerBuffer> spb;
 	spb.instance();
 	spb->data=data;
+	return spb;
 }