refactor: reduce #ifdef ENABLE_EXTERNAL_SIGNER usage

In particular this make the node interface independent on whether external signer support is compiled.

src/qt/createwalletdialog.cpp

@@ -112,7 +112,6 @@ CreateWalletDialog::~CreateWalletDialog()
     delete ui;
 }
 
-#ifdef ENABLE_EXTERNAL_SIGNER
 void CreateWalletDialog::setSigners(std::vector<ExternalSigner>& signers)
 {
     if (!signers.empty()) {
@@ -132,7 +131,6 @@ void CreateWalletDialog::setSigners(std::vector<ExternalSigner>& signers)
         ui->external_signer_checkbox->setEnabled(false);
     }
 }
-#endif
 
 QString CreateWalletDialog::walletName() const
 {

src/qt/createwalletdialog.h

@@ -7,11 +7,8 @@
 
 #include <QDialog>
 
-class WalletModel;
-
-#ifdef ENABLE_EXTERNAL_SIGNER
 class ExternalSigner;
-#endif
+class WalletModel;
 
 namespace Ui {
     class CreateWalletDialog;
@@ -27,9 +24,7 @@ public:
     explicit CreateWalletDialog(QWidget* parent);
     virtual ~CreateWalletDialog();
 
-#ifdef ENABLE_EXTERNAL_SIGNER
     void setSigners(std::vector<ExternalSigner>& signers);
-#endif
 
     QString walletName() const;
     bool isEncryptWalletChecked() const;

src/qt/walletcontroller.cpp

@@ -296,7 +296,6 @@ void CreateWalletActivity::create()
 {
     m_create_wallet_dialog = new CreateWalletDialog(m_parent_widget);
 
-#ifdef ENABLE_EXTERNAL_SIGNER
     std::vector<ExternalSigner> signers;
     try {
         signers = node().externalSigners();
@@ -304,7 +303,6 @@ void CreateWalletActivity::create()
         QMessageBox::critical(nullptr, tr("Can't list signers"), e.what());
     }
     m_create_wallet_dialog->setSigners(signers);
-#endif
 
     m_create_wallet_dialog->setWindowModality(Qt::ApplicationModal);
     m_create_wallet_dialog->show();