/_node/<nodename>/_system endpoint returns HTTP 500 when TLS is configured

## Description

1. Setup a clustered CouchDB environment with TLS configured in `etc/vm.args`
```
# Snippet from our vm.args
-pa /opt/opsview/erlang/lib/erlang/lib/ssl-9.6/ebin
-proto_dist inet_tls
-ssl_dist_optfile /opt/opsview/datastore/etc/ssl.args
-ssl session_lifetime 300
```
2. Attempt to call the `_node//_system` endpoint.

`curl user:password@localhost:5984/_node//_system`
```json
{
"error": "invalid_ejson",
"reason": "{badrpc,\n {'EXIT',\n {function_clause,\n [{prim_inet,getstat,\n [<0.328.0>,\n [recv_oct,recv_cnt,recv_max,recv_avg,recv_dvi,send_oct,\n send_cnt,send_max,send_avg,send_pend]],\n []},\n {chttpd_node,'-get_distribution_stats/0-fun-0-',1,\n [{file,\"src/chttpd_node.erl\"},{line,278}]},\n {lists,map,2,[{file,\"lists.erl\"},{line,1239}]},\n {chttpd_node,get_stats,0,\n [{file,\"src/chttpd_node.erl\"},{line,230}]},\n {rpc,local_call,3,[{file,\"rpc.erl\"},{line,321}]},\n {chttpd_node,call_node,4,\n [{file,\"src/chttpd_node.erl\"},{line,187}]},\n {chttpd_node,handle_node_req,1,\n [{file,\"src/chttpd_node.erl\"},{line,119}]},\n {chttpd,handle_req_after_auth,2,\n [{file,\"src/chttpd.erl\"},{line,323}]}]}}}",
"ref": 1035438607
}
```

## Expected Behaviour

Endpoint shouldn't return an HTTP 500 status and should contain the expected data [as documented](https://docs.couchdb.org/en/latest/api/server/common.html#node-node-name-system).

## Your Environment

`localhost:5984/`
```json
{
"couchdb": "Welcome",
"version": "3.1.1",
"git_sha": "ce596c65d",
"uuid": "41595977eddf264776561a5e3f4060b5",
"features": [
"access-ready",
"partitioned",
"pluggable-storage-engines",
"reshard",
"scheduler"
],
"vendor": {
"name": "The Apache Software Foundation"
}
}
```
`localhost:5984/_membership`
```json
{
"all_nodes": [
"couchdb@jl-42569-solo-ds-1.os.opsview.com",
"couchdb@jl-42569-solo-ds-2.os.opsview.com",
"couchdb@jl-42569-solo-orch.os.opsview.com"
],
"cluster_nodes": [
"couchdb@jl-42569-solo-ds-1.os.opsview.com",
"couchdb@jl-42569-solo-ds-2.os.opsview.com",
"couchdb@jl-42569-solo-orch.os.opsview.com"
]
}
```

* CouchDB version used: 3.1.1
* Operating system and version: Ubuntu 18.04.5 LTS
* Erlang Version: 22 **and** 21

## Additional Context

TLS is set up and enabled for communication between all nodes.

Spoke a fair bit with jan and rnewson on the CouchDB slack, it seems like Erlang 22.x has changed `dist_ctrl` a fair bit causing compatability issues with the current implementation of `chttpd_node`.

Start in src/chttpd_node.erl at get_distribution_stats/0 around line 278 and trace how handle_node_req/1 reaches it for TLS-configured nodes; the reported failure is in prim_inet:getstat on the distribution connection. Done means the _node//_system endpoint no longer returns HTTP 500 and contains the documented system data.

Written by the indexing model from the issue text.