From Gerri: fix TFileCollection::Merge() which was progressively duplicating the objects already in the list.
From Gerri:
fix TFileCollection::Merge() which was progressively duplicating the objects already
in the list.



git-svn-id: ecbadac9c76e8cf640a0bca86f6bd796c98521e3@41745 27541ba8-7e3a-0410-8455-c3a389f83636

bbannier/ROOT,bbannier/ROOT,bbannier/ROOT,bbannier/ROOT,bbannier/ROOT,bbannier/ROOT,bbannier/ROOT