Changing javagiac.dll's to the latest version in desktop/kickstart.xml

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34648 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Fixing NPE and better handling of undefined in Prover

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34649 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e