Add labels for atlassian/confluence:8.5.2

[westonsteimel]

We should add labels for a confluence image (with CPE matching enabled for java) since there are currently alot of false positives surfaced by this image, but also the true positives will not currently be covered by the GitHub data.

[joshbressers]

This is a good candidate https://hub.docker.com/r/atlassian/confluence-server/