Ticket #3268: fixed the bug

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@26770 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
[giac] fix for chi2 test, not linked to ggb

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@26772 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e