Site should not have to be initialized before accessing management console

Created by: slimsag

If you start a sourcegraph instance, it is impossible to access the management console until you create an admin account. In some situations, this is confusing and unexpected (e.g. if you are going through the steps a second time to set up your real instance).

Additionally, the global_state table is weird because despite representing one consistent state, only the last entry in the table is the current site state which is odd and leads to the table sometimes having hundreds of rows and various different site IDs. It is unclear to me why it was written this way (performance?) or if this is a bug.