Revert "add RN field to signed proto"

This reverts commit dc199ef.

Author: xtaci

message.pb.go

@@ -44,10 +44,8 @@ message SignedProto {
 	// signature r,s for prefix+messages+version+x+y above
 	bytes r = 5;
 	bytes s = 6;
-	// optional auxcilliary data set externally(such as: block)
+	// Auxcilliary Data set by user, and send along the signedproto
 	bytes AuxData = 7;
-	// optional random number set externally(such as: hash)
-	bytes RN = 8;
 }
 
 // MessageType defines supported message types