Better settings for a newly created VM

Now a standalone VM not cloned from a template
will not have a kernel and have HVM virt mode.

fixes QubesOS/qubes-issues#5203

qubesmanager/create_new_vm.py

@@ -153,9 +153,12 @@ class NewVmDlg(QtGui.QDialog, Ui_NewVMDlg):
 
         properties = {}
         properties['provides_network'] = self.provides_network.isChecked()
+
         if self.netvm.currentIndex() != 0:
             properties['netvm'] = self.netvm_list[self.netvm.currentIndex()]
-        if self.install_system.isChecked():
+
+        # Standalone - not based on a template
+        if self.vm_type.currentIndex() == 2:
             properties['virt_mode'] = 'hvm'
             properties['kernel'] = None