Merge 1409726 from trunk:

* support/rotatelogs.c (post_rotate): Really omit the second arg when
  invoking a post-rotate program, rather than passing an empty arg.
  (Fixes to code match desired&documented behaviour.)

Reviewed by: jorton, jim, sf


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1416406 13f79535-47bb-0310-9956-ffa450edef68