fix: always show searchbar in global navbar on sourcegraph.com
Created by: attfarhan
Fixes a bug where the search bar doesn't appear on sourcegraph.com for logged out users.
@eseliger and I tried to find the last "good" commit so we could bisect and find the root cause, but it appeared to be a bug as far back as 3.8. This should at least fix the immediate problem.
Context: https://sourcegraph.slack.com/archives/CMT39K56Z/p1576889557007700