Release v2.1.6

@JnMik

Changelog

1.13.9: Both release executables and Docker images are built with this Go release.

Ability to specify TLS configuration for the account resolver. Thanks to @JnMik for the report (#1272):

resolver_tls {
  cert_file: ...
  key_file: ...
  ca_file: ...
}

Client IP (client_ip) in the server's INFO sent to clients. Client libraries may expose that in the future (#1293)
Option trace_verbose and command line parameters -VV and -DVV to increase trace and debug verbosity. By default system account messages will not be traced unless this option is enabled (#1295)
Value of GOMAXPROCS in /varz monitoring output (#1304)
Option to include subscription details in monitoring endpoints /routez and /connz. For instance /connz?subs=detail will now return not only the subjects of the subscription, but the queue name (if applicable) and some other details (#1318)

Recover from panics during configuration parsing and instead issue errors (#1274)
Parse ping_interval as a duration. If not a duration, falls back to interpret as the number of seconds (#1281)
Error trace in case protocol exceeds the max control line value (#1286)
TLS version 1.3 and cipher names in log/monitoring. Thanks to @burner-account for the report (#1316)

Include port on the "Connected leafnode" INF notice in the server log (#1303)
Some dependencies. This covers the golang crypto package CVE. Note that the CVE mentions the ssh package, which NATS Server does not use, so it should not be affected. Thanks to @KauzClay for the contribution (#1320)

Server did not exit after receiving the lame duck mode signal. This is a regression introduced in v2.1.2 (#1276)
Use configured ping interval for clients that have not yet sent the CONNECT protocol. When the CONNECT protocol is received, a ping will be sent to the client in a short period of time to establish the initial TTL for this client (#1289)
A configuration producing a warning causes -DV to be ignored (#1291)
Incorrect buffer reuse in case of partial connection write (#1298)
Configuration reload of debug/trace option was not applied to existing clients (#1300)
Loop detection for LeafNodes (#1308)
Use account resolver URL from the operator JWT if one is specified. Note that if one is explicitly configured with the "resolver" option, it will take precedence (#1318)