Added English localization for "orchestration"

core/src/main/resources/hudson/model/Messages.properties

@@ -311,6 +311,7 @@ UpdateCenter.PluginCategory.listview-column=List view columns
 UpdateCenter.PluginCategory.maven=Maven
 UpdateCenter.PluginCategory.misc=Miscellaneous
 UpdateCenter.PluginCategory.notifier=Build Notifiers
+UpdateCenter.PluginCategory.orchestration=Orchestration
 UpdateCenter.PluginCategory.page-decorator=Page Decorators
 UpdateCenter.PluginCategory.parameter=Build Parameters
 UpdateCenter.PluginCategory.post-build=Other Post-Build Actions