Enable firewall for all hosts

Signed-off-by: Florian Pritz <bluewind@xinu.at>

group_vars/all/common.yml

 dns_search_domain: "archlinux.org"
+
+configure_firewall: true
+
+# this is needed to make ansible find the firewalld python
+# module when deploying firewalld tasks
+ansible_python_interpreter: /usr/bin/python3.7