use http rather than https for ubuntu cloud images.
use http rather than https for ubuntu cloud images.

using http by default means benefit of caching proxies.

Also here, remove FIXME comment that is now fixed.

Signed-off-by: Scott Moser <a546549d5d9f07bf2bb68f2090e57413e6aba263@ubuntu.com>

atxwebs/lxd,hallyn/lxd,akshaykarle/lxd,yura-pakhuchiy/lxd,erikmack/lxd,pcdummy/lxd,Malizor/lxd,georghopp/lxd,lxc/lxd,mjeanson/lxd,atxwebs/lxd,lxc/lxd,Skarlso/lxd,techtonik/lxd,ericsnowcurrently/lxd,stgraber/lxd,hallyn/lxd,lxc/lxd,akshaykarle/lxd,atxwebs/lxd,achanda/lxd,hallyn/lxd,stgraber/lxd,achanda/lxd,ericsnowcurrently/lxd,yura-pakhuchiy/lxd,georghopp/lxd,ollie314/lxd,chrisglass/lxd,techtonik/lxd,yura-pakhuchiy/lxd,Malizor/lxd,Malizor/lxd,chrisglass/lxd,lxc/lxd,dustinkirkland/lxd,mjeanson/lxd,stgraber/lxd,lxc/lxd,stgraber/lxd,dustinkirkland/lxd,erikmack/lxd,lxc/lxd,Skarlso/lxd,mjeanson/lxd,dustinkirkland/lxd,ollie314/lxd,stgraber/lxd,georghopp/lxd,hallyn/lxd,erikmack/lxd,jsavikko/lxd,ollie314/lxd,pcdummy/lxd,Skarlso/lxd,hallyn/lxd,stgraber/lxd,pcdummy/lxd,ericsnowcurrently/lxd,jsavikko/lxd,jsavikko/lxd,stgraber/lxd,Skarlso/lxd,chrisglass/lxd,techtonik/lxd,lxc/lxd,atxwebs/lxd,akshaykarle/lxd,achanda/lxd,hallyn/lxd