pom.xml: downgrade commons-httpclient to 3.0.1
pom.xml: downgrade commons-httpclient to 3.0.1

We don't need 3.1, 3.0.x is good enough and unifies dependencies
across projects.

Signed-off-by: Pierre-Alexandre Meyer <ff019a5748a52b5641624af88a54a2f0e46a9fb5@ning.com>

pierre/eventtracker