restore backward comp with the old Hudson class

core/src/main/java/hudson/model/Hudson.java

@@ -299,4 +299,18 @@ public class Hudson extends Jenkins {
     static {
         XSTREAM.alias("hudson",Hudson.class);
     }
+
+    /**
+     * @deprecated  only here for backward comp
+     */
+    public static final class MasterComputer extends Jenkins.MasterComputer {
+        // no op
+    }
+
+    /**
+     * @deprecated  only here for backward comp
+     */
+    public static class CloudList extends Jenkins.CloudList {
+        // no op
+    }
 }

core/src/main/java/jenkins/model/Jenkins.java

@@ -3297,8 +3297,8 @@ public class Jenkins extends AbstractCIBase implements ItemGroup<TopLevelItem>,
         return getPrimaryView();
     }
 
-    public static final class MasterComputer extends Computer {
-        private MasterComputer() {
+    public static class MasterComputer extends Computer {
+        protected MasterComputer() {
             super(Jenkins.getInstance());
         }