Skip a few SQL queries for cross project gantt.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@4515 e93f8b46-1217-0410-a6f0-8f06a7374b81

lib/redmine/helpers/gantt.rb

@@ -206,7 +206,7 @@ module Redmine
         project.children.visible.has_module('issue_tracking').each do |project|
           render_project(project, options)
           return if abort?
-        end
+        end unless project.leaf?
 
         # Remove indent to hit the next sibling
         options[:indent] -= options[:indent_increment]