Remove Diablo compatibility options
Remove Diablo compatibility options

According to the fixme in the code, these should have been removed
in Folsom.

Change-Id: If11c576e45931b72c227f51a0b8f63bc5f7dd4cb

mat128/python-novaclient,takeshineshiro/python-novaclient,ntt-sic/python-novaclient,citrix-openstack-build/python-novaclient,metacloud/python-novaclient,akash1808/python-novaclient,metacloud/python-novaclient,Shihta/python-novaclient,Shihta/python-novaclient,guptaankita/python-novaclient,CCI-MOC/python-novaclient,akash1808/python-novaclient,JioCloud/python-novaclient,mat128/python-novaclient,citrix-openstack-build/python-novaclient,guptaankita/python-novaclient,ntt-sic/python-novaclient,CCI-MOC/python-novaclient,JioCloud/python-novaclient,takeshineshiro/python-novaclient