Remove an ineffective assignment to `*err_desc`.
Remove an ineffective assignment to `*err_desc`.

h2o/h2o,h2o/h2o,h2o/h2o,devnexen/h2o,devnexen/h2o,devnexen/h2o,yannick/h2o,h2o/h2o,yannick/h2o,yannick/h2o,devnexen/h2o,devnexen/h2o,yannick/h2o,h2o/h2o,devnexen/h2o,yannick/h2o,devnexen/h2o,h2o/h2o,yannick/h2o,yannick/h2o,h2o/h2o,h2o/h2o,devnexen/h2o,yannick/h2o,devnexen/h2o,yannick/h2o,h2o/h2o