Remove mox3
Remove mox3

Drop mox3 from lower-constraints.txt.

Change-Id: I835b6a1260f228ff14dc5339240654183c451f67
Signed-off-by: Chuck Short <61c7e57c8f71fbf1f6c3fcd85c16ccd0f494e116@redhat.com>

openstack/cinder,mahak/cinder,mahak/cinder,openstack/cinder