[giac] make limit((sinh(sin(x))-sin(sinh(x)))/(tanh(tan(x))-tan(tanh(x))),x,0) work

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@37772 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e