Redundant <html> tag removed from context menu.

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24777 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Redundant quotation marks removed from disabled menuitem too.

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24778 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e