Move c++20 initializers out of for statement

This does not work with gcc 4.8 so let us avoid it as
the improvement is minimal.

src/dialogs/subkeyswidget.cpp

@@ -215,7 +215,8 @@ void SubKeysWidget::setKey(const GpgME::Key &key)
         QByteArray(currentItem->data(0, Qt::UserRole).value<GpgME::Subkey>().fingerprint()) : QByteArray();
     d->ui.subkeysTree->clear();
 
-    for (const auto subkeys = key.subkeys(); const auto &subkey : subkeys) {
+    const auto subkeys = key.subkeys();
+    for (const auto &subkey : subkeys) {
         auto item = new QTreeWidgetItem;
         item->setData(0, Qt::DisplayRole, Formatting::prettyID(subkey.keyID()));
         item->setData(0, Qt::AccessibleTextRole, Formatting::accessibleHexID(subkey.keyID()));

src/utils/gui-helper.cpp

@@ -141,7 +141,8 @@ void Kleo::unsetDefaultButtons(const QDialogButtonBox *buttonBox)
     if (!buttonBox) {
         return;
     }
-    for (const auto buttons = buttonBox->buttons(); auto button : buttons) {
+    const auto buttons = buttonBox->buttons();
+    for (auto button : buttons) {
         if (auto pushButton = qobject_cast<QPushButton *>(button)) {
             pushButton->setDefault(false);
         }
@@ -153,7 +154,8 @@ void Kleo::unsetAutoDefaultButtons(const QDialog *dialog)
     if (!dialog) {
         return;
     }
-    for (const auto pushButtons = dialog->findChildren<QPushButton *>(); auto pushButton : pushButtons) {
+    const auto pushButtons = dialog->findChildren<QPushButton *>();
+    for (auto pushButton : pushButtons) {
         pushButton->setAutoDefault(false);
     }
 }