roles/common: rework fail2ban again

Actually, we do want to run fail2ban on all hosts because the sshd
monitoring via systemd is nice. At the very least it reduces spam
from failed logins in our systemd journal.

roles/common/handlers/main.yml

@@ -25,4 +25,3 @@
   ansible.builtin.systemd:
     name: fail2ban
     state: restarted
-  when: webserver is defined and webserver == 'nginx'