JIRA build for 4.2.1 is broken due to missing gson artifact in atlassian repo

The JIRA build fails due to a missing artifact from the repository.

Either it should be there, or the confluence page on buidling jira should be updated.

[exec] [INFO] Failed to resolve artifact.
[exec]
[exec] Missing:
[exec] ----------
[exec] 1) com.google.code.gson:gson:jar:1.4
[exec]
[exec] Try downloading the file manually from the project website.
[exec]
[exec] Then, install it using the command:
[exec] mvn install:install-file -DgroupId=com.google.code.gson -Dartif
actId=gson -Dversion=1.4 -Dpackaging=jar -Dfile=/path/to/file
[exec]
[exec] Alternatively, if you host your own repository you can deploy the f
ile there:
[exec] mvn deploy:deploy-file -DgroupId=com.google.code.gson -Dartifac
tId=gson -Dversion=1.4 -Dpackaging=jar -Dfile=/path/to/file -Durl=[url] -Dreposi
toryId=[id]
[exec]
[exec] Path to dependency:
[exec] 1) com.atlassian.maven.plugins:sandbox-maven-plugin:maven-plugin
:2.0-beta12
[exec] 2) com.google.code.gson:gson:jar:1.4
[exec]
[exec] ----------
[exec] 1 required artifact is missing.
[exec]
[exec] for artifact:
[exec] com.atlassian.maven.plugins:sandbox-maven-plugin:maven-plugin:2.0-b
eta12
[exec]
[exec] from the specified remote repositories:
[exec] central (https://m2proxy.atlassian.com/repository/public),
[exec] atlassian-m1-repository (https://m2proxy.atlassian.com/repository/m
1/)
[exec]
[exec]