Create gdm3 custom.conf file if it doesn't exist

Author: nickygerritsen

icpc-wf/ansible/common_tasks_prebuild.yml

@@ -95,6 +95,7 @@
         path: /etc/gdm3/custom.conf
         regexp: 'AutomaticLoginEnable'
         line: 'AutomaticLoginEnable=true'
+        create: yes
       notify: restart gdm
 
     - name: Automatically login domjudge user