Add missing null pointer protection


git-svn-id: https://root.cern.ch/svn/root/trunk@48595 27541ba8-7e3a-0410-8455-c3a389f83636
In UpdateClassInfo add support for template and nested classes by getting their fully qualified name to search for the TClass (however this does not yet work for collection of Double32_t ...)


git-svn-id: https://root.cern.ch/svn/root/trunk@48596 27541ba8-7e3a-0410-8455-c3a389f83636