NIC Release v5.2.1

[danielnginx]

Tasks

• QE sign off - ensure that we are shipping without bugs and we have the latest base OS images
• Security sign-off - ensure that we are not shipping any fixable CVE's and if we have CVE's they are documented and internal security clearance is done
• Docs release notes & Changelog
• Release Operator

Test and update NGINX Agent
Test and update WAF and DOS