Please add "block" to Refernce Card

[Benjamin Mesing <bensmail@gmx.net>]

URL: http://www.debian.org/Bugs/server-refcard

Please add 
        block bugnumber by bugnumber bugnumber ...
to the page.
See http://kitenet.net/~joey/blog/entry/bts_blockers_support.html for
more information or
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=320867;msg=9 for an
example.

Thanks
Ben