eyre: upon login redirect parameter being empty, redirect to /
complete=%.y
==
::
+ =/ actual-redirect ?:(=(u.redirect '') '/' u.redirect)
%- handle-response
:* %start
:- status-code=307
^= headers
- :~ ['location' u.redirect]
+ :~ ['location' actual-redirect]
['set-cookie' cookie-line]
==
data=~
