[giac] fix for previous change for #4330 

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34171 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Checking r23998 and r24003 for #3106 (both are OK)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34172 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e