main: init SNTP before starting network

If we want to use an NTP server provided by DHCP, sntp_servermode_dhcp()
should be called before the DHCP client requests an IP.

main/main.c

@@ -80,6 +80,8 @@ void app_main(void)
 
     ESP_ERROR_CHECK(esp_netif_init());
 
+    init_sntp();
+
     esp_err_t err = nvs_flash_init();
     if (err == ESP_ERR_NVS_NO_FREE_PAGES) {
         // NVS partition was truncated and needs to be erased
@@ -152,8 +154,6 @@ void app_main(void)
         vTaskDelay(portMAX_DELAY);
     }
 
-    init_sntp();
-
     char *command_endpoint = config_get_char("command_endpoint", DEFAULT_COMMAND_ENDPOINT);
     if (strcmp(command_endpoint, "Home Assistant") == 0) {
         init_hass();