bugfix2372 - ft_timelockgrandaverage discards field trial if present in varargin (ft_timelockanalysis keeptrials = yes)

git-svn-id: svn+ssh://svn.fcdonders.nl/home/svnroot/fieldtrip/trunk@9755 0cf7c7f0-3615-4144-b4e6-68da3bce3cd0