Fix signal handling in saccept for windows

Reviewed-by: Nicola Tuveri <nic.tuv@gmail.com>
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Paul Dale <ppzgs1@gmail.com>
Reviewed-by: Tom Cosgrove <tom.cosgrove@arm.com>
(Merged from https://github.com/openssl/openssl/pull/24047)

demos/bio/saccept.c

@@ -34,6 +34,9 @@ static void interrupt(int sig)
 
 static void sigsetup(void)
 {
+#if defined(OPENSSL_SYS_WINDOWS)
+    signal(SIGINT, interrupt);
+#else
     struct sigaction sa;
 
     /*
@@ -43,6 +46,7 @@ static void sigsetup(void)
     sa.sa_handler = interrupt;
     sigemptyset(&sa.sa_mask);
     sigaction(SIGINT, &sa, NULL);
+#endif
 }
 
 int main(int argc, char *argv[])