backup: simplify ordering of restoring VMs

No other change than reducing two nested loops into one.

qubes/backup.py

@@ -2110,16 +2110,12 @@ class BackupRestore(object):
             return
 
         # First load templates, then other VMs
-        for do_templates in (True, False):
-            if self.canceled:
-                break
-            for vm in vms.values():
+        for vm in sorted(vms.values(), key=lambda x: x.is_template(),
+                reverse=True):
             if self.canceled:
                 # only break the loop to save qubes.xml
                 # with already restored VMs
                 break
-                if vm.is_template() != do_templates:
-                    continue
             self.log.info("-> Restoring {0}...".format(vm.name))
             retcode = subprocess.call(
                 ["mkdir", "-p", os.path.dirname(vm.dir_path)])