ovs: Support Linux Kernel 4.4.0-66-generic
ovs: Support Linux Kernel 4.4.0-66-generic

Digital Ocean has upgraded to the latest 4.4 kernel, so our OVS
container needs to be updated to reflect that.

kklin/quilt,tejasmanohar/quilt,NetSys/quilt,LuiseV/quilt,kayousterhout/quilt,kklin/kelda,quilt/quilt,ejj/quilt-dev,tejasmanohar/quilt,NetSys/quilt,kklin/quilt,kelda/kelda,kayousterhout/quilt,kklin/kelda,LuiseV/quilt,kklin/kelda,NetSys/quilt,kelda/kelda,quilt/quilt,kelda/kelda,LuiseV/quilt,LuiseV/quilt,kelda/kelda,kayousterhout/quilt,ejj/quilt-dev,tejasmanohar/quilt,kklin/quilt,ejj/quilt-dev,kklin/quilt,ejj/quilt-dev,quilt/quilt,LuiseV/quilt,tejasmanohar/quilt,NetSys/quilt,quilt/quilt,kklin/kelda,NetSys/quilt,kayousterhout/quilt