mqtt: updated to latest version to include latest fixes, support for global CA store, extended error structure to receive mqtt specific errors. updated idf ssl example to use this error struct

https://github.com/espressif/esp-mqtt/issues/135

components/mqtt/esp-mqtt

@@ -1 +1 @@
-Subproject commit fb3d2107cdac440d84f2fab81ea9b5217aa4ba1f
+Subproject commit e3b013e2db58124ea68cf7c8f44a8cba6e1572b7

examples/protocols/mqtt/ssl/main/app_main.c

@@ -80,10 +80,14 @@ static esp_err_t mqtt_event_handler_cb(esp_mqtt_event_handle_t event)
             break;
         case MQTT_EVENT_ERROR:
             ESP_LOGI(TAG, "MQTT_EVENT_ERROR");
-            int mbedtls_err = 0;
-            esp_err_t err = esp_tls_get_and_clear_last_error(event->error_handle, &mbedtls_err, NULL);
-            ESP_LOGI(TAG, "Last esp error code: 0x%x", err);
-            ESP_LOGI(TAG, "Last mbedtls failure: 0x%x", mbedtls_err);
+            if (event->error_handle->error_type == MQTT_ERROR_TYPE_ESP_TLS) {
+                ESP_LOGI(TAG, "Last error code reported from esp-tls: 0x%x", event->error_handle->esp_tls_last_esp_err);
+                ESP_LOGI(TAG, "Last tls stack error number: 0x%x", event->error_handle->esp_tls_stack_err);
+            } else if (event->error_handle->error_type == MQTT_ERROR_TYPE_CONNECTION_REFUSED) {
+                ESP_LOGI(TAG, "Connection refused error: 0x%x", event->error_handle->connect_return_code);
+            } else {
+                ESP_LOGW(TAG, "Unknown error type: 0x%x", event->error_handle->error_type);
+            }
             break;
         default:
             ESP_LOGI(TAG, "Other event id:%d", event->event_id);