[Tock Studio] Fix empty namespace not appearing as selected

[DylanCLINCHAMP]

Hi,
With a fresh install, the checkbox does not appear as selected until an application is creating inside that namespace (at http://[tock admin domain]/configuration/namespaces ). That issue occurs both with the default namespace and with "manually" created namespaces while they're empty (first and second screenshots). Once we create an application in that namespace, the checkbox appears as selected (third screenshot).

[rkuffer]

Fixed by #1547