Made blog_url becalled just once...

...and stored in the `url` variable.

Rakefile

@@ -337,8 +337,9 @@ task :setup_github_pages, :repo do |t, args|
       end
     end
   end
+  url = blog_url(user, project)
   jekyll_config = IO.read('_config.yml')
-  jekyll_config.sub!(/^url:.*$/, "url: #{blog_url(user, project)}")
+  jekyll_config.sub!(/^url:.*$/, "url: #{url}")
   File.open('_config.yml', 'w') do |f|
     f.write jekyll_config
   end
@@ -358,7 +359,7 @@ task :setup_github_pages, :repo do |t, args|
       f.write rakefile
     end
   end
-  puts "\n---\n## Now you can deploy to #{blog_url(user, project)} with `rake deploy` ##"
+  puts "\n---\n## Now you can deploy to #{url} with `rake deploy` ##"
 end
 
 def ok_failed(condition)