High severity vulnerability in netmask dependency

[joebernard]

[email protected] relies on netmask via pac-resolver. The version being used is vulnerable to exploit as documented here:

GHSA-pch5-whg9-qr2r

Please update the package to avoid the vulnerability.

[dentuzhik]

It seems that the source of vulnerability, which was superagent-proxy package, has been fixed in code-push dependency itself, so this package just needs to bump a version of codepush:
https://github.com/microsoft/code-push/pull/759/files#diff-7ae45ad102eab3b6d7e7896acd08c427a9b25b346470d7bc6507b6481575d519R30

I created a PR and let's home some folks from MS can merge it soon
#2066