Remove useless username parameter from add_remote
Remove useless username parameter from add_remote

Per review on 3275

Change-Id: Id62de897130cd64b2a83a26f0085618097b7c524

meelapshah/git-review,openstack-infra/git-review,ka2m/git-review,meelapshah/git-review,entropia1/git-review,jeeloo/git-review