Fix bus error in mod_socache_shmcb due to a misalignment

in some 32 bit builds, especially on Solaris Sparc.

PR 53040.

Backport of r1373270 from trunk.

Submitted by: rjung
Reviewed by: rpluem, trawick


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1373439 13f79535-47bb-0310-9956-ffa450edef68