Add missing default variable

defaults/main.yml

@@ -12,6 +12,9 @@ wireguard_port: "51820"
 # The default interface name that wireguard should use if not specified otherwise.
 wireguard_interface: "wg0"
 
+# Whether or not WireGuard is running in a container
+wireguard_containerized: "false"
+
 
 #######################################
 # Settings only relevant for Ubuntu