[BUG] Loading information from the agent info endpoint not retrieving statsd port

[scott-shields-github]

The agent /info endpoint returns data in a way that is slightly different than the trace library decodes it. Specifically, the statsd port in located in a nested config object.

Version of dd-trace-go
v1.48.0

Describe what happened:
When loading data from the /info endpoint, the statsd port is not retrieved correctly

Describe what you expected:
The statsd port should be correctly retrieved

Steps to reproduce the issue:
Create an instance of a tracer with an agent with a non-default statsd port, notice that the statsd port is not configured correctly in the tracer logs.

root@hostl:/# curl localhost:8126/info
{
	"version": "7.40.1",
	"git_commit": "05a524c",
	"endpoints": [
		"/v0.3/traces",
		"/v0.3/services",
		"/v0.4/traces",
		"/v0.4/services",
		"/v0.5/traces",
		"/v0.7/traces",
		"/profiling/v1/input",
		"/telemetry/proxy/",
		"/v0.6/stats",
		"/v0.1/pipeline_stats",
		"/appsec/proxy/",
		"/evp_proxy/v1/",
		"/evp_proxy/v2/",
		"/debugger/v1/input",
		"/dogstatsd/v1/proxy",
		"/config/set"
	],
	"feature_flags": [
		""
	],
	"client_drop_p0s": true,
	"span_meta_structs": true,
	"long_running_spans": true,
	"config": {
		"default_env": "prod",
		"target_tps": 10,
		"max_eps": 200,
		"receiver_port": 8126,
		"receiver_socket": "",
		"connection_limit": 0,
		"receiver_timeout": 0,
		"max_request_bytes": 52428800,
		"statsd_port": 8215,
		"max_memory": 0,
		"max_cpu": 0,
		"analyzed_spans_by_service": {},
		"obfuscation": {
			"elastic_search": false,
			"mongo": false,
			"sql_exec_plan": false,
			"sql_exec_plan_normalize": false,
			"http": {
				"remove_query_string": false,
				"remove_path_digits": false
			},
			"remove_stack_traces": false,
			"redis": false,
			"memcached": false
		}
	}
}

2023/03/14 17:10:23 Datadog Tracer v1.43.1 INFO: DATADOG TRACER CONFIGURATION
...
...
"agent_features":{"DropP0s":true,"Stats":true,"StatsdPort":0}}

Additional environment details (Version of Go, Operating System, etc.):
go 1.20
centos