Merge r1811569 from trunk:

* The calculation of the sizes was flawed:
  The index tells us the size of the node in 4096 byte pages minus 1.
  Hence we need to multiply back with 4096 aka << 12 (plus adding the
  missing page).

Submitted by: rpluem


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1811642 13f79535-47bb-0310-9956-ffa450edef68