fixed another compilation failure

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@15679 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/Functions.java

@@ -1040,7 +1040,7 @@ public class Functions {
         return PageDecorator.all();
     }
     
-    public static DescriptorList<Cloud> getCloudDescriptors() {
+    public static List<Descriptor<Cloud>> getCloudDescriptors() {
         return Cloud.all();
     }