[NTG-context] Generic fontloader and flush_components

Hi, in font-ots.lua (which becomes part of the generic fontloader) nuts.flush_components is used, while it seems to be defined for mkiv and generic in node-gcm.lua, but this file is not included in the packaged generic fontloader. Therefore the current luatex-fonts-merged.lua breaks with "trying to call a nil value (upvalue flush_components)". Could you please add a definition for nuts.flush_components in the generic version? Thanks, Marcel