Fix problem with last commit.


git-svn-id: https://fricas.svn.sourceforge.net/svnroot/fricas/trunk@1559 b0c55286-4f34-0410-a049-a1e7e93b0762
Fix another problem with r1557.


git-svn-id: https://fricas.svn.sourceforge.net/svnroot/fricas/trunk@1560 b0c55286-4f34-0410-a049-a1e7e93b0762