[#1923] Set default profile.Version only if empty

Author: placer14

core/profile.go

@@ -67,7 +67,10 @@ func (n *OpenBazaarNode) UpdateProfile(profile *pb.Profile) error {
 		return err
 	}
 
-	profile.Version = ListingVersion
+	if profile.GetVersion() == 0 {
+		profile.Version = ListingVersion
+	}
+
 	profile.BitcoinPubkey = hex.EncodeToString(mPubkey.SerializeCompressed())
 	m := jsonpb.Marshaler{
 		EnumsAsInts:  false,