I suggest inserting the following code into socketmodule.c:

CHANGE:
#ifdef  TCP_KEEPCNT    
        PyModule_AddIntMacro(m, TCP_KEEPCNT);
#endif

TO:
#ifdef  TCP_KEEPCNT    
    #if defined(_MSC_VER) && _MSC_VER >= 1800
    // Windows 10 1703 (15063)
    if (IsWindows10CreatorsOrGreater()) {
        PyModule_AddIntMacro(m, TCP_KEEPCNT);        
    }
    #endif
#endif

AND CHANGE:
#ifdef  TCP_FASTOPEN
        PyModule_AddIntMacro(m, TCP_FASTOPEN);
#endif

TO:
#ifdef  TCP_FASTOPEN
    #if defined(_MSC_VER) && _MSC_VER >= 1800
    // Windows 10 1703 (Build: 14393)
    if (IsWindows10AnniversaryOrGreater()) {
        PyModule_AddIntMacro(m, TCP_FASTOPEN);
    }
    #endif 
#endif