Fix the defaults yaml that broke with the multiline var

roles/netbootxyz/defaults/main.yml

@@ -68,11 +68,7 @@ custom_generate_menus: false
 custom_github_menus: true
 custom_templates_dir: '{{ netbootxyz_conf_dir }}/custom'
 custom_url_menus: true
-early_menu_contents: '### early menu overrides
-
-  ### used to set early ipxe options such as custom console & logo
-
-  '
+early_menu_contents: '### used to set early ipxe options such as custom console & logo'
 early_menu_enabled: false
 generate_checksums: true
 generate_disks: true