Fixed error message for missing option config (missing space, wrong name)

expconfig.py

@@ -359,8 +359,8 @@ class ExpConfig(ConfigObj):
                 split_jobs(pre_config)
                 register_version(pre_config, config_versions)
             else:
-                feedback.warning("cannot find option config for '%s', using"+
-                                 "default/experiment only", experiment_type)
+                feedback.warning("cannot find config for option '%s', using "+
+                                 "default/experiment type only", option)
 
         # Read host environment settings from library