HTTP/2 502 Bad Gateway on `some https://forum.nim-lang.org/posts.json?id=<ID>`
Google "nim destroy ref object", first result: https://forum.nim-lang.org/t/4132

Got error and invite to send issue here.
Here what I see in firefox dev tools

```
XHR GET https://forum.nim-lang.org/posts.json?id=4132
[HTTP/2 502 Bad Gateway 306ms]

	
GET
	https://forum.nim-lang.org/posts.json?id=4132
Status
502
Bad Gateway
VersionHTTP/2
Transferred5.87 KB (5.36 KB size)
Referrer Policystrict-origin-when-cross-origin

    	
    cache-control
    	private, max-age=0, no-store, no-cache, must-revalidate, post-check=0, pre-check=0
    cf-ray
    	6d5514d1fe227729-LHR
    content-type
    	text/html; charset=UTF-8
    date
    	Sat, 29 Jan 2022 20:06:29 GMT
    expires
    	Thu, 01 Jan 1970 00:00:01 GMT
    referrer-policy
    	same-origin
    server
    	cloudflare
    set-cookie
    	cf_ob_info=502:6d5514d1fe227729:LHR; path=/; expires=Sat, 29-Jan-22 20:06:59 GMT
    set-cookie
    	cf_use_ob=443; path=/; expires=Sat, 29-Jan-22 20:06:59 GMT
    X-Firefox-Spdy
    	h2
    x-frame-options
    	SAMEORIGIN
    	
    Accept
    	*/*
    Accept-Encoding
    	gzip, deflate, br
    Accept-Language
    	en-US,en;q=0.5
    Cache-Control
    	no-cache
    Connection
    	keep-alive
    Cookie
    	_ga=<*HIDE*>
    Host
    	forum.nim-lang.org
    Pragma
    	no-cache
    Referer
    	https://forum.nim-lang.org/t/4132
    Sec-Fetch-Dest
    	empty
    Sec-Fetch-Mode
    	cors
    Sec-Fetch-Site
    	same-origin
    TE
    	trailers
    User-Agent
    	Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:96.0) Gecko/20100101 Firefox/96.0
```