productBuild: variable is in the config object

Change-Id: I7d882cf116fe319c133d7832cefa06e61ad44848
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
diff --git a/vars/productBuild.groovy b/vars/productBuild.groovy
index 22971f0..64e8947 100644
--- a/vars/productBuild.groovy
+++ b/vars/productBuild.groovy
@@ -47,7 +47,7 @@
 				tooling.cloneAndCheckout(config.repoPath, env.GERRIT_BRANCH, '+refs/heads/*:refs/remotes/origin/*');
 			}
 			def ownVersion = lib.getOwnVersion('pom.xml')
-			def publishFolder = "/${publishRoot}/" + lib.getPublishFolder(ownVersion)
+			def publishFolder = "/${config.publishRoot}/" + lib.getPublishFolder(ownVersion)
 			def publishDirectory = '/home/data/httpd/download.eclipse.org' + publishFolder
 			def upstreamVersion = config.upstreamVersion
 			if (!upstreamVersion) {