#3824 fix

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30556 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Bugfix for #3530.
(The problem was:
1. click into the last row,
2. click on "use as text" button,
3. edit the text,
4. press enter
Most of cases the text in the cell won't be the updated text, but it will the same as was before the 3. point.)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30557 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e