message: Fix compile error in Visual Studio 2017 15.1
diff: @@ -204,7 +204,7 @@ namespace vcpkg::Install
  {
  // The VS2015 standard library requires comparison operators of T and U
  // to also support comparison of T and T, and of U and U, due to debug checks.
  -#if _MSC_VER < 1910
  +#if _MSC_VER <= 1910
  bool operator()(const std::string& lhs, const std::string& rhs) { return lhs < rhs; }
  bool operator()(const file_pack& lhs, const file_pack& rhs) { return lhs.first < rhs.first; }
  #endif
  