testnode: support empty software_path_list

erp5/util/testnode/SlapOSControler.py

@@ -253,7 +253,7 @@ class SlapOSControler(object):
   def initializeSlapOSControler(self, slapproxy_log=None, process_manager=None,
         reset_software=False, software_path_list=None):
     self.process_manager = process_manager
-    self.software_path_list = software_path_list
+    self.software_path_list = software_path_list or []
     self.log('SlapOSControler, initialize, reset_software: %r' % reset_software)
     config = self.config
     slapos_config_dict = self.config.copy()