Fixed: Deleting a subtasks doesn't update parent's rgt & lft values, introduced by r5286 (#9577).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@7814 e93f8b46-1217-0410-a6f0-8f06a7374b81

vendor/plugins/awesome_nested_set/lib/awesome_nested_set.rb

@@ -444,7 +444,7 @@ module CollectiveIdea #:nodoc:
         # Prunes a branch off of the tree, shifting all of the elements on the right
         # back to the left so the counts still work.
         def prune_from_tree
-          return if right.nil? || left.nil? || leaf? || !self.class.exists?(id)
+          return if right.nil? || left.nil? || !self.class.exists?(id)
 
           self.class.base_class.transaction do
             reload_nested_set