Fixes the build on 12.04 via Jenkins

After an extremely long and painful day of pouring through debian
packages, sdist, pbr, pip, setup.py, and so forth, I found that I
can get horizon to happily build simply by ensuring that these
lines are set.

Change-Id: If3f304d085d196e26f829c0efab176576451daf8
Fixes: ENG-80