Removed one exception

Hello,

An exception was throwed in `jekyll/lib/converible.rb`, line 81 when there was a Liquid error:

```ruby
begin
 self.content = Liquid::Template.parse(self.content).render(payload, info)
rescue => e
 puts "Liquid Exception: #{e.message} in #{self.name}"
 #  The variable self.name was not found 
end
```
I replaced `self.name` by `@name` and now it works.