Prevent failure in the I/O due to a confusion between a class (for example SiStripDigi) and

a nested class with the same name (for example: PGlobalDigi::SiStripDigi) which resulted
in the former to have its ClassInfo pointing to the later after an (unrelated) reload.


git-svn-id: http://root.cern.ch/svn/root/trunk@37556 27541ba8-7e3a-0410-8455-c3a389f83636