The GitLabServer configuration name should be unique. A unique is generated automatically. But if the user wishes to change the field to an existing server name, there isn't a possible method to check if the server name already exist. Need to find a hack to this. Saving this for later as user do not generally have any incentive to change the name of server.
Presently, if a user names a gitlab server with the same name then only the oldest server with the name is persisted. No warning is shown at the runtime.