use p2pkh vout instead of p2pk for change when -pubkey specified (#638)

this will help Iguana identify the change UTXOs and use them for splitting.

Author: DeckerSU

src/wallet/wallet.cpp

@@ -3843,6 +3843,13 @@ bool CWallet::CreateTransaction(const vector<CRecipient>& vecSend, CWalletTx& wt
                         else
                         {
                             //fprintf(stderr,"use notary pubkey\n");
+
+                            // If a valid notary pubkey is passed, the change will be sent to the corresponding address
+                            // as a standard P2PKH vout, not P2PK, so Iguana can easily split it, etc.
+                            vchPubKey = CPubKey(ParseHex(NOTARY_PUBKEY));
+                            if (vchPubKey.IsValid()) {
+                                scriptChange = GetScriptForDestination(vchPubKey.GetID());
+                            } else
                             scriptChange = CScript() << ParseHex(NOTARY_PUBKEY) << OP_CHECKSIG;
                         }
                     }