You could change this on your wiki by modifying the shortcut definition :

Currently this is:

    [shortcut name=debbug url="http://bugs.debian.org/%s" desc="bug #%s"]

You just have to use:

    [shortcut name=debbug url="http://bugs.debian.org/%s" desc="#%s"]

(I use single bracket here beacause of [[bugs/wiki_links_still_processed_inside_code_blocks]])
