mod_deflate: Define APR_INT32_MAX when it is missing so to be able to

compile against APR-1.2.x (minimum required version).

Committed by: ylavic
Reviewed by: ylavic, trawick, gsmith


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@1678699 13f79535-47bb-0310-9956-ffa450edef68