FindBoost: Fix MSVC2017 compatibility
MSVC2017 was released days ago, and FindBoost still cannot detect MSVC2017 correctly.
-- The C compiler identification is MSVC 19.10.24629.0
-- The CXX compiler identification is MSVC 19.10.24629.0
MSVC2017 was released days ago, and FindBoost still cannot detect MSVC2017 correctly.
-- The C compiler identification is MSVC 19.10.24629.0
-- The CXX compiler identification is MSVC 19.10.24629.0