SSTP is using the same certificate that is used by DirectAccess for IP-HTTPS. You should use the server role management console ...

SSTP is using the same certificate that is used by DirectAccess for IP-HTTPS. You should use the server role management console to modify the IP-HTTPS certificate in case you wish to change the certificate to be used by SSTP. If you proceed with changing the certificate, DirectAccess clients may not be able to connect to the server using the IP-HTTPS interface. Are you sure you wish to continue?