bugfix(1508, testscript failed): ft_selectdata now throws an error in case requested channel/channelcmb selection is not present in the data


git-svn-id: svn+ssh://svn.fcdonders.nl/home/svnroot/fieldtrip/trunk@9765 0cf7c7f0-3615-4144-b4e6-68da3bce3cd0