tags field appends wrong datatype and the alert is being rejected by OpsGenie API

[Exequiel Pierotto]

Using the snippet example:

{
  "opsgenie": {
    "customerKey": "the-key",
    "teams": ["teams"],
    "recipients": "the-recipients",
    "source": "alert-source",
    "overwrite_quiet_hours": true,
    "tags": ["sensu"]
  }
}

Tags is an array of strings and in this line it's appending the config['opsgenie']['tags'] into tags array

Which creates:
"tags":[["sensu"],"OverwriteQuietHours","critical"]

It should be:
tags + json_config['tags'] if json_config['tags']

Alerts are rejected by OpsGenie API with the message:
HTTP 422 Unprocessable Entity