Use the given mysql host

tasks/main.yml

@@ -86,7 +86,7 @@
 - name: Set the correct db host # noqa 208
   lineinfile:
     path: /srv/AKPlanning/AKPlanning/settings_production.py
-    line: "        'HOST': 'instance',"
+    line: "        'HOST': '{{ hostvars[akplanning_mariadb_host]['ansible_default_ipv4']['address'] }}',"
     regexp: "^        'HOST':"
   notify: restart akplanning