message: Fix compilation on case-sensitive filesystems
diff: @@ -24,7 +24,7 @@ TEST_CASE("executable") {
  #ifdef _WIN32
  #define WIN32_LEAN_AND_MEAN
  DOCTEST_MAKE_STD_HEADERS_CLEAN_FROM_WARNINGS_ON_WALL_BEGIN
  -#include <Windows.h>
  +#include <windows.h>
  DOCTEST_MAKE_STD_HEADERS_CLEAN_FROM_WARNINGS_ON_WALL_END
  #ifdef _MSC_VER
  #define LoadDynamicLib(lib) LoadLibrary(lib ".dll")
  