link to boost 1.67 instead of 1.68
link to boost 1.67 instead of 1.68

it seems like boost 1.68 has issues with msvc and c++17
hemirt/chatterino2,hemirt/chatterino2,Cranken/chatterino2,Cranken/chatterino2,Cranken/chatterino2,fourtf/chatterino2,hemirt/chatterino2,fourtf/chatterino2,fourtf/chatterino2,Cranken/chatterino2,hemirt/chatterino2