Revert to the old TLS API, but keep certs as mg_str for DER

examples/mqtt-client/main.c

@@ -28,6 +28,12 @@ static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
   if (ev == MG_EV_OPEN) {
     MG_INFO(("%lu CREATED", c->id));
     // c->is_hexdumping = 1;
+  } else if (ev == MG_EV_CONNECT) {
+    if (mg_url_is_ssl(s_url)) {
+      struct mg_tls_opts opts = {.ca = mg_unpacked("/certs/ca.pem"),
+                                 .name = mg_url_host(s_url)};
+      mg_tls_init(c, &opts);
+    }
   } else if (ev == MG_EV_ERROR) {
     // On error, log error message
     MG_ERROR(("%lu ERROR %s", c->id, (char *) ev_data));
@@ -101,9 +107,6 @@ int main(int argc, char *argv[]) {
   signal(SIGTERM, signal_handler);  // manager loop on SIGINT and SIGTERM
 
   mg_mgr_init(&mgr);
-
-  struct mg_tls_opts opts = {.client_ca = mg_unpacked("/certs/client_ca.pem")};
-  mg_tls_ctx_init(&mgr, &opts);
   mg_timer_add(&mgr, 3000, MG_TIMER_REPEAT | MG_TIMER_RUN_NOW, timer_fn, &mgr);
   while (s_signo == 0) mg_mgr_poll(&mgr, 1000);  // Event loop, 1s timeout
   mg_mgr_free(&mgr);                             // Finished, cleanup