[Bug]: Can't open Config Page after update on 2.0
### What happened?

After installing update 2.0, the configuration page for the plugin doesn't open. In the homebridge log I find this message:

[30/05/2022, 09:53:43] [Homebridge UI] [homebridge-eufy-security] /usr/local/lib/node_modules/homebridge-eufy-security/homebridge-ui/server.js:107
      this.config['country'] = body.country ??= 'US';
                                            ^^^
SyntaxError: Unexpected token '??='
    at wrapSafe (internal/modules/cjs/loader.js:988:16)
    at Module._compile (internal/modules/cjs/loader.js:1036:27)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1101:10)
    at Module.load (internal/modules/cjs/loader.js:937:32)
    at Function.Module._load (internal/modules/cjs/loader.js:778:12)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:76:12)
    at internal/main/run_main_module.js:17:47

It looks like a syntax error, or it's a new syntax an I have an old node.js version?



### Device Type

Doorbell (Supported)

### Plugin Version

v2.0.x (Supported)

### HomeBridge Version

v1.4.x (Supported)

### NodeJS Version

v14 (Supported)

### Operating System

Raspbian 10+ (Supported)

### Relevant log output

```shell
[30/05/2022, 09:53:43] [Homebridge UI] [homebridge-eufy-security] Child process ended
[30/05/2022, 09:53:56] [Homebridge UI] [homebridge-eufy-security] Terminating child process...
homebridge : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/bin/kill -9 5318
pam_unix(sudo:session): session opened for user root by (uid=0)
pam_unix(sudo:session): session closed for user root
homebridge : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/bin/kill -9 5442
pam_unix(sudo:session): session opened for user root by (uid=0)
pam_unix(sudo:session): session closed for user root
[30/05/2022, 09:58:08] [Homebridge UI] [homebridge-eufy-security] /usr/local/lib/node_modules/homebridge-eufy-security/homebridge-ui/server.js:107
      this.config['country'] = body.country ??= 'US';
                                            ^^^
SyntaxError: Unexpected token '??='
    at wrapSafe (internal/modules/cjs/loader.js:988:16)
    at Module._compile (internal/modules/cjs/loader.js:1036:27)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1101:10)
    at Module.load (internal/modules/cjs/loader.js:937:32)
    at Function.Module._load (internal/modules/cjs/loader.js:778:12)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:76:12)
    at internal/main/run_main_module.js:17:47
[30/05/2022, 09:58:08] [Homebridge UI] [homebridge-eufy-security] Child process ended
[30/05/2022, 09:58:17] [Homebridge UI] [homebridge-eufy-security] Terminating child process...
```
