Fix for #3006 [needs backport]

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@23224 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Fixed warnings

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@23225 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e