extra: enable debug options for apt(8)

Sometimes jobs on CI with Jepsen tests failed on installation
dependencies:

```
sudo -S -u root bash -c "cd /; env DEBIAN_FRONTEND=noninteractive apt-get install -y --force-yes apt-transport-https libzip4 ntpdate faketime"

STDIN:
null

STDOUT:
Reading package lists...
Building dependency tree...
Reading state information...

STDERR:
W: --force-yes is deprecated, use one of the options starting with --allow instead.
E: Unable to locate package libzip4
E: Unable to locate package ntpdate
E: Unable to locate package faketime
```

Problem looks as a flaky, I couldn't reproduce it locally.  I suspect
the root cause is an infrastructure problem and to get more details
about it I have enabled debug options in apt-get and added
`set -o errexit` as it is recommended in documentation [1]
(see Note section).

1. https://www.terraform.io/docs/language/resources/provisioners/remote-exec.html#argument-reference

Part of: tarantool/jepsen.tarantool#87

(cherry picked from commit f40afb8)

Author: ligurio

extra/tf/main.tf

@@ -27,8 +27,9 @@ resource "openstack_compute_instance_v2" "instance" {
 
   provisioner "remote-exec" {
     inline = [
+      "set -o errexit",
       "sudo hostnamectl set-hostname n${count.index + 1}",
-      "sudo apt-get update"
+      "sudo apt-get -o Debug::Acquire::http=true -o Debug::pkgAcquire::Worker=1 update"
     ]
   }