instead of setsockopt_string, encode topic and use setsockopt
instead of setsockopt_string, encode topic and use setsockopt

acc7260 was bad - it blows up in Python 2 because there the
value is not a unicode, and setsockopt_string only accepts
unicodes. Making the value a unicode on Python 2 without
crashing in Python 3 attempting to decode a str is annoying,
so instead let's encode the topic and use setsockopt.

This will blow up in Python 3 if the topic is already encoded,
but I don't think that should happen.

maxamillion/fedmsg,chaiku/fedmsg,chaiku/fedmsg,maxamillion/fedmsg,fedora-infra/fedmsg,fedora-infra/fedmsg,chaiku/fedmsg,pombredanne/fedmsg,fedora-infra/fedmsg,pombredanne/fedmsg,pombredanne/fedmsg,maxamillion/fedmsg