@Rektalizer Evidently you have a mish mash of "names" here:
irrisuite.ru - as noted above, this one resolves to IP address 126.96.36.199
www.irrisuite.ru -- this one also resolves to IP address 188.8.131.52
forum.irrisuite.ru -- this one resolves to ... same as before.
Which are you actually using? If you intend to use more than one of the above then which will be your nodebb forums URL?
Or is it your intention to have ALL of the above point to your nodebb forums? Note that this can create issues on down the road if, for e.g., you decide to "spin off" www for e.g. a blog or other purposes.
As for your nginx logs immediately up post, have you adjusted your nginx server_name config to jive with your nodebb config.json yet?