Have a look at netmenu.c in <xephemroot>/GUI/xephem.
Change the following code at line 87 na beyond:
???????? ssl_method = SSLv23_client_method();??? /* deprecated since openssl 1.1.x */
//??? ??? ssl_method = TLS_client_method();??? /* since openssl 1.1.x */
to
// ??????? ssl_method = SSLv23_client_method();??? /* deprecated since openssl 1.1.x */
??? ??? ssl_method = TLS_client_method();??? /* since openssl 1.1.x */
Hope that helps.