src/vs/server/node/extensionHostConnection.ts/readCaseInsensitive
function readCaseInsensitive(env: { [key: string]: string | undefined }, key: string): string | undefined {
	const pathKeys = Object.keys(env).filter(k => k.toLowerCase() === key.toLowerCase());
	const pathKey = pathKeys.length > 0 ? pathKeys[0] : key;
	return env[pathKey];
}