The zulip user has no need to see this file; it's used by nginx.
And when we set up the cert early in install, there's no zulip user
yet anyway, so this fails.
Thanks to the magic of `set -x`, I noticed this:
```
+ cat
++ ssl-cert
/tmp/src/zulip-server/scripts/setup/generate-self-signed-cert: line 49: ssl-cert: command not found
+ apt-get install -y openssl
[...]
```
In other words, we were trying to run `ssl-cert` -- the name of a
Debian package I meant to refer to in a comment inside the templated
temporary config file for `openssl req` -- as if it were a command.
It wasn't, hence the error.
Because `set -e` has loopholes like a sieve, this didn't cause the
script to exit, just produced this funny output and presumably caused
the config file's comment to be missing a word. In principle, it
could do something surprising if for some reason there were a command
named `ssl-cert` on PATH.
Fix it.
This gives us just one way of adopting a self-signed cert, rather than
one script which would generate a new one and an option to another
which would symlink to the system's snakeoil cert. Now those two
codepaths converge, and do the same thing.
The small advantage of generating our own over the alternative is that
it lets us set the name in the cert to EXTERNAL_HOST, rather than the
system's hostname as embedded in the system snakeoil certs. Not a big
deal, but might make things go slightly smoother if some browsers are
lenient (in a way that they probably shouldn't be.)
Greg Price