Fix new crash on startup for Windows build

load_cfg() calls free_cfg() before do_cryptInit() is called, so the ssl_rwlock
was uninitialized here.

src/sbbs3/load_cfg.c

@@ -349,12 +349,14 @@ void prep_cfg(scfg_t* cfg)
 void free_cfg(scfg_t* cfg)
 {
 #if defined(SBBS) && defined(USE_CRYPTLIB)
+	if(cfg->prepped) {
 		lock_ssl_cert();
 		if (cfg->tls_certificate != -1 && cfg->prepped) {
 			cryptDestroyContext(cfg->tls_certificate);
 			cfg->tls_certificate = -1;
 		}
 		unlock_ssl_cert();
+	}
 #endif
 	free_node_cfg(cfg);
 	free_main_cfg(cfg);