general: output content fix for mod_fastcgi + mod_deflate as this calculates the wrong content-length, see also: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=509116

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@5544 1f8fe7d8-47f0-464c-8d0a-336f4953ab05