Fix typo

Author: plusjade

Rakefile

@@ -52,7 +52,7 @@ task :post do
     puts "Error - date format must be YYYY-MM-DD, please check you typed it correctly!"
     exit -1
   end
-  filename = File.join(CONFIG['posts'], "##{date}-#{slug}.#{CONFIG['post_ext']}")
+  filename = File.join(CONFIG['posts'], "#{date}-#{slug}.#{CONFIG['post_ext']}")
   if File.exist?(filename)
     abort("rake aborted!") if ask("#{filename} already exists. Do you want to overwrite?", ['y', 'n']) == 'n'
   end