Merge r1850834 from trunk:

* modules/md/md_acme_drive.c (acme_driver_init):
  Remove written-but-not-read variable (gcc 8.x warning).

Submitted by: jorton
Reviewed by: jailletc36, jim, ylavic


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1851526 13f79535-47bb-0310-9956-ffa450edef68