add Czech customized error messages

Submitted by: Marcel Kolaja <xkolaja@aurora.fi.muni.cz>
Reviewed by: Martin Povoln� <xpovolny@aurora.fi.muni.cz>


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@99957 13f79535-47bb-0310-9956-ffa450edef68