tests/lib/prepare-utils.sh: make tweaks script more robust

As ssh might not be active yet when we ask it to reload its
configuration. This provoked an initialization error so the
"Initialize system state" change had to be retried, delaying the test
around 7 minutes.

tests/lib/prepare-utils.sh

@@ -326,7 +326,8 @@ echo 'ubuntu ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers.d/99-ubuntu-user
 sed -i 's/\#\?\(PermitRootLogin\|PasswordAuthentication\)\>.*/\1 yes/' /etc/ssh/sshd_config
 echo "MaxAuthTries 120" >> /etc/ssh/sshd_config
 grep '^PermitRootLogin yes' /etc/ssh/sshd_config
-systemctl reload ssh
+# ssh might not be active yet so the command might fail
+systemctl reload ssh || true
 
 print_system "done setting up ssh for spread test user"