Removing check for unsupported Django version
Removing check for unsupported Django version

Horizon no longer supports Django 1.5 and less, so this logic is
unnecessary.

Closes-Bug: #1502206
Change-Id: I7b892760e23f697c6af0ae005f56e9566beb069e

maestro-hybrid-cloud/horizon,redhat-openstack/horizon,redhat-cip/horizon,yeming233/horizon,ChameleonCloud/horizon,redhat-cip/horizon,dan1/horizon-x509,sandvine/horizon,NeCTAR-RC/horizon,noironetworks/horizon,redhat-openstack/horizon,Mirantis/mos-horizon,bac/horizon,Tesora/tesora-horizon,ChameleonCloud/horizon,wolverineav/horizon,bigswitch/horizon,Mirantis/mos-horizon,redhat-cip/horizon,django-leonardo/horizon,davidcusatis/horizon,dan1/horizon-x509,yeming233/horizon,NeCTAR-RC/horizon,openstack/horizon,noironetworks/horizon,Mirantis/mos-horizon,gerrive/horizon,bac/horizon,sandvine/horizon,bac/horizon,coreycb/horizon,gerrive/horizon,gerrive/horizon,BiznetGIO/horizon,yeming233/horizon,django-leonardo/horizon,openstack/horizon,dan1/horizon-x509,noironetworks/horizon,dan1/horizon-x509,openstack/horizon,BiznetGIO/horizon,openstack/horizon,yeming233/horizon,bac/horizon,davidcusatis/horizon,sandvine/horizon,Tesora/tesora-horizon,bigswitch/horizon,NeCTAR-RC/horizon,Tesora/tesora-horizon,coreycb/horizon,noironetworks/horizon,maestro-hybrid-cloud/horizon,davidcusatis/horizon,sandvine/horizon,django-leonardo/horizon,wolverineav/horizon,bigswitch/horizon,redhat-cip/horizon,Tesora/tesora-horizon,maestro-hybrid-cloud/horizon,davidcusatis/horizon,Mirantis/mos-horizon,gerrive/horizon,maestro-hybrid-cloud/horizon,wolverineav/horizon,django-leonardo/horizon,redhat-openstack/horizon,bigswitch/horizon,coreycb/horizon,BiznetGIO/horizon,wolverineav/horizon,ChameleonCloud/horizon,BiznetGIO/horizon,redhat-openstack/horizon,ChameleonCloud/horizon,coreycb/horizon,NeCTAR-RC/horizon