small fix in assertion made in CHILD functor
fixes compilation error when using e.g F.CHILD(1, F.Z) - F.Z
/data/home/mstahl/stack/Rec/InstallArea/x86_64_v2-centos7-gcc11-opt/include/Functors/Adapters.h:138:35: error: static assertion failed
138 | static_assert( std::is_same_v<decltype( mask ), bool> );
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/data/home/mstahl/stack/Rec/InstallArea/x86_64_v2-centos7-gcc11-opt/include/Functors/Adapters.h:138:35: note: 'std::is_same_v<const bool&, bool>' evaluates to false