nit(opsgenie): add config access requirement to error text

[mifu67]

Users who set up their Opsgenie API keys via the Opsgenie API were experiencing problems due to a lack of configuration access. However, the error message that they encountered did not indicate that this was the problem, so this PR makes the issue more clear.

[cathteng]

what is configuration access? do you have a link

[mifu67]

{
  "type": "Sentry",
  "name": "SentryIntegrationAPI",
  "ownerTeam": {
    	"name": "[TEAM NAME]"
    },
  "allowReadAccess" : true,
	"allowWriteAccess" : true,
	"allowDeleteAccess" : false,
	"allowConfigurationAccess" : true,
  "ignoreRespondersFromPayload": false,
  "ignoreTeamsFromPayload": false,
  "suppressNotifications": false
}

Configuration access is necessary to hit the key authentication endpoint (https://api.opsgenie.com/v2/integrations/authenticate). If allowConfigurationAccess is set to false, then the following response results:

{
    "code": 40301,
    "message": "API Key is not granted with configuration access.",
    "took": 0.001,
    "requestId": "ee466ef4-c807-438e-b70c-b642f52e90b4"
}

[mifu67]

This is specifically for key creation via the API; keys created in the Opsgenie UI seem to have configuration access enabled automatically

[cathteng]

do we need to point them to documentation?

[mifu67]

The Opsgenie docs don't say anything about needing config access to authenticate. It could be helpful to point to the Sentry docs. What do you think?