fixed a bug that causes tardis to throw an exception when the user runs an experiment search when he/she doesn't have access to any experiments
fixed a bug that causes tardis to throw an exception when the user runs an experiment search when he/she doesn't have access to any experiments

git-svn-id: f4d1588b67b337f21bf9858517edaebb1de6e9c8@254 1bbb43ac-ffe0-11de-8c0c-f1c8ac664a8e

grischa/mytardis-mrtardis,grischa/mytardis-mrtardis