Some PHP update has changed the behavior of referencing a missing key in
an array, so the mechanism I was using to specify the default login page
tab was bugged (emitting errors) and did not allow to manually switch to
signup after the app is initialized.

To fix this, simply define the missing values to empty strings.

Signed-off-by: Malfurious <m@lfurio.us>

Signed-off-by: Malf Furious <m@lfurio.us>

Now reloading current path after successful login, instead of
redirecting to app-root.