Update obfs4proxy package in debian

Right now the obfs4proxy package is about a year out of date. This is known and the Debian ticket for it is here: 948312.

Since more recent versions use utls, this requires some new packages to be added. I've filed the following itp for yawning's fork of utls: 954209. From what I can tell, we'll need at least two more packages as well.

I've been chipping away at this, slowly, but if someone else wants to pick it up that's great.