Return OK response unless something grave has happened

@@ -60,5 +60,7 @@ imap4d_lsub (struct imap4d_command *command, char *arg)
       fclose (fp);
       fclose (fp);
       return util_finish (command, RESP_OK, "Completed");
       return util_finish (command, RESP_OK, "Completed");
     }
     }
+  else if (errno == ENOENT)
+    return util_finish (command, RESP_OK, "Completed");
   return util_finish (command, RESP_NO, "Can not list subscriber");
   return util_finish (command, RESP_NO, "Can not list subscriber");
 }
 }