wallet: Create a SilentPaymentsSPKM by default

Author: achow101

src/wallet/wallet.cpp

@@ -3727,6 +3727,13 @@ void CWallet::SetupDescriptorScriptPubKeyMans()
         master_key.SetSeed(seed_key);
 
         SetupDescriptorScriptPubKeyMans(master_key);
+
+        // Also setup a SilentPaymentsSPKM
+        auto sp_spkm = std::unique_ptr<SilentPaymentsSPKM>(new SilentPaymentsSPKM(*this, m_keypool_size, master_key));
+        uint256 id = sp_spkm->GetID();
+        AddScriptPubKeyMan(id, std::move(sp_spkm));
+        AddActiveScriptPubKeyMan(id, OutputType::SILENT_PAYMENT, /*internal=*/false);
+        AddActiveScriptPubKeyMan(id, OutputType::SILENT_PAYMENT, /*internal=*/true);
     } else {
         ExternalSigner signer = ExternalSignerScriptPubKeyMan::GetExternalSigner();