Remove duplication from utils/settings.py
Remove duplication from utils/settings.py

We dont need to specify a filename for those packages that already have
a MAIN defined.

Change-Id: I84e7edbad6b57a37374c1d8591e1ebaab02298b2

noironetworks/horizon,yeming233/horizon,ChameleonCloud/horizon,BiznetGIO/horizon,noironetworks/horizon,BiznetGIO/horizon,ChameleonCloud/horizon,NeCTAR-RC/horizon,ChameleonCloud/horizon,ChameleonCloud/horizon,NeCTAR-RC/horizon,yeming233/horizon,yeming233/horizon,yeming233/horizon,NeCTAR-RC/horizon,noironetworks/horizon,openstack/horizon,openstack/horizon,BiznetGIO/horizon,NeCTAR-RC/horizon,openstack/horizon,noironetworks/horizon,BiznetGIO/horizon,openstack/horizon