include_code tag in liquid_tags plugin output wrong "download" link

[fehiepsi]

With the new change in pelican 3.3, there is no longer static directory. The include_code tag imports code just fine but gives the wrong "download" link.
E.g.: instead of http://localhost:8000/downloads/code/foo.py, the download link is: http://localhost:8000/static/downloads/code/foo.py

Other tags seem work well.

[talha131]

@fehiepsi will you please test my pull request?

[fehiepsi]

@talha131 I have test your pull request. The issue is fixed now. Thank you a lot.