TMVA generated class does not compile, and unable to read xml file when using Keras interface

@willemv
Check my topic[1]

The class present a typo that prevents it to compile, sadly even fixing the typo does not allow to use the standalone class since the definitions of the functions
Initialize()
GetMvaValue__(std::vector<double, std::allocator<double> > const&) const
Clear()
are completely missing.