Don't use time_t in scfg_t definition

sbbsctrl.exe is built with Borland C++ still which only has a 32-bit time_t, so to keep the scfg_t definition compatible between MSVC and Borland builds, use time32_t (32-bit time_t) values only.

This fixes the reported sbbsctrl.exe error:
Error loading configuration
cfg->size (23944) != sizeof(scfg_t) (23952)

Introduced in commit e535aaac.
Reported via DOVE-Net by  Daryl Stout (TBOLT), confirmed by Nightfox (DIGDIST).

src/sbbs3/scfgdefs.h

@@ -620,7 +620,7 @@ typedef struct
 
 	// Run-time state information (not configuration)
 	int				tls_certificate;
-	time_t                  tls_cert_file_date;
+	time32_t        tls_cert_file_date;
 
 } scfg_t;
 

src/sbbs3/ssl.c

@@ -291,7 +291,7 @@ CRYPT_CONTEXT get_ssl_cert(scfg_t *cfg, char **estr, int *level)
 		return -1;
 	pthread_mutex_lock(&ssl_cert_mutex);
 	SAFEPRINTF2(str,"%s%s",cfg->ctrl_dir,"ssl.cert");
-	time_t fd = fdate(str);
+	time32_t fd = (time32_t)fdate(str);
 	if (cfg->tls_certificate != -1 || !cfg->prepped) {
 		if (fd == cfg->tls_cert_file_date) {
 			pthread_mutex_unlock(&ssl_cert_mutex);