MCHANGES-341 Externalize JIRA server timeout values to the configuration section.

AdaptiveJiraDownloader is a proxy, so settings have to be pushed down into the
final target RestJiraDownloader.

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1626972 13f79535-47bb-0310-9956-ffa450edef68