Fixed errors with virt mode choice

Current virtualization mode wasn't displayed correctly. It should work now.

fixes QubesOS/qubes-issues#3517

qubesmanager/settings.py

@@ -631,7 +631,7 @@ class VMSettingsWindow(ui_settingsdlg.Ui_SettingsDialog, QtGui.QDialog):
 
         try:
             if self.virt_mode.currentIndex() != self.virt_mode_idx:
-                self.vm.virt_mode = self.selected_virt_mode().lower()
+                self.vm.virt_mode = self.selected_virt_mode()
         except Exception as ex:  # pylint: disable=broad-except
             msg.append(str(ex))
 

qubesmanager/utils.py

@@ -60,6 +60,8 @@ def prepare_choice(widget, holder, propname, choice, default,
             oldvalue = qubesadmin.DEFAULT
         else:
             oldvalue = getattr(holder, propname)
+            if transform is not None and oldvalue is not None:
+                oldvalue = transform(oldvalue)
     else:
         oldvalue = object()  # won't match for identity
     idx = 0