Failure to recover if network is not available on startup
# Bug Report

### Describe the Bug
It appears that if Homebridge boots on system start, and the network connection is not immediately available, the Ring plugin will get stuck in a loop where it claims the Ring API endpoints are not reachable. I never had any issues with this setup on a Raspberry Pi, but I recently migrated my setup to a Mac mini for more resources, and it consistently happens every time my Mac starts.

### To Reproduce
Steps to reproduce the behavior:
 - Start Homebridge on macOS boot
 - Attempt to allow Ring plugin to load
 - See error

### Expected behavior
Ring plugin should automatically recover even if network connectivity was not initially available.

### Screenshots/Logs
[Ring] Failed to reach Ring server at https://app.ring.com/rhq/v1/devices/v1/locations.  cacheableLookup ENOTFOUND app.ring.com.  Trying again in 5 seconds...

This log line is printed over and over until rebooting Homebridge.

### Additional context
My Mac mini is setup with a wired connection, and automatically logs in without password on boot. All other plugins are able to start and recover from any initial errors. Restarting Homebridge after system boot resolves the issue.

### Homebridge Ring Config
Post homebridge-ring platform config  _without sensitive information_
```

{
  "refreshToken": "xxx",
  "platform": "Ring"
}

```

### Environment
 - OS: macOS Catalina
 - Node.js: 12.18.3
 - NPM: 6.14.6
 - homebridge-ring: 9.9.0
 - homebridge: 1.2.2
 - hoobs: N/A
