The undocumented _DISABLE_FEED_BROWSER option added in commit
c39befacb2 turns off the UI for looking
at which feeds other users are subscribed to, but it did not prevent
you from manually constructing an RPC call to get the same data. This
was a privacy risk for those who consider _DISABLE_FEED_BROWSER
important.
Signed-off-by: Anders Kaseorg <andersk@mit.edu>