Fix gravatar relative_url error in network graph
If relative_url_root set, the web site of icon is "/gitlabhttps://secure.gravatar.com/avatar/xxxxx" in the network graph. The fourth commit in https://github.com/gitlabhq/gitlabhq/issues/7800
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
If relative_url_root set, the web site of icon is "/gitlabhttps://secure.gravatar.com/avatar/xxxxx" in the network graph. The fourth commit in https://github.com/gitlabhq/gitlabhq/issues/7800