Allow running nuxeo-doc job on 6.0 branch

11:39:41 [ERROR] Failed to execute goal on project nuxeo-platform-categorization-language: Could not resolve dependencies for project org.nuxeo.ecm.platform:nuxeo-platform-categorization-language:jar:6.0-HF18-SNAPSHOT: Could not find artifact org.nuxeo.ecm.platform:nuxeo-platform-categorization-service:jar:6.0-HF18-SNAPSHOT in public-snapshots-mirror (http://maven.in.nuxeo.com/nexus/content/groups/public-snapshot) -> [Help 1]

10:02:53 [ERROR] Failed to execute goal on project nuxeo-runtime: Could not resolve dependencies for project org.nuxeo.runtime:nuxeo-runtime:jar:6.0-HF19-SNAPSHOT: Could not find artifact org.nuxeo.common:nuxeo-common:jar:6.0-HF19-SNAPSHOT in public-snapshots-mirror (http://maven.in.nuxeo.com/nexus/content/groups/public-snapshot) -> [Help 1]
10:02:53 [ERROR] 
10:02:53 [ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
10:02:53 [ERROR] Re-run Maven using the -X switch to enable full debug logging.
10:02:53 [ERROR] 
10:02:53 [ERROR] For more information about the errors and possible solutions, please read the following articles:
10:02:53 [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/DependencyResolutionException
10:02:53 [ERROR] 
10:02:53 [ERROR] After correcting the problems, you can resume the build with the command
10:02:53 [ERROR]   mvn <goals> -rf :nuxeo-runtime