Add Confluent products/services to the list

[Valentin Crettaz]

Confluent has issued a security advisory concerning CVE-2021-44228. It seems that mostly connectors are impacted:
https://support.confluent.io/hc/en-us/articles/4412615410580-CVE-2021-44228-log4j2-vulnerability

[Maarten Aertsen]

hi @consulthys! Thanks for another contribution. Would you mind submitting a PR? Thanks!