Fixes typescript build failure comparing null | undefined

[toddheslin]

@mhamas I came across an issue deploying this today, so I've made a patch for you.

The key issue is that in node_modules/apify/types/proxy_configuration.d.ts, we have:

export function createProxyConfiguration(proxyConfigurationOptions?: ProxyConfigurationOptions | undefined): Promise<ProxyConfiguration | null>;

Meaning proxyConfigurationObject is maybe null:

But in node_modules/apify/types/crawlers/puppeteer_crawler.d.ts, we have:

proxyConfiguration?: any;

Which means it could be set or undefined, but not null:

The nullish-colleasing patch means if it's null, we make it undefined to keep TS happy.

Turning:

into:

[mhamas]

Great catch, many thanks.