mailman3: Update paths to match the official mailman-web package

mailman-web has been packaged in the community repo and it uses
different paths than my homebrewed PKGBUILD.

roles/mailman3/tasks/main.yml

@@ -8,8 +8,8 @@
   loop:
     - {src: mailman.cfg.j2, dest: /etc/mailman.cfg, group: mailman}
     - {src: mailman-hyperkitty.cfg.j2, dest: /etc/mailman-hyperkitty.cfg, group: mailman}
-    - {src: settings.py.j2, dest: /etc/mailman3/settings.py, group: mailman-web}
-    - {src: urls.py.j2, dest: /etc/mailman3/urls.py, group: mailman-web}
+    - {src: settings.py.j2, dest: /etc/webapps/mailman-web/settings.py, group: mailman-web}
+    - {src: urls.py.j2, dest: /etc/webapps/mailman-web/urls.py, group: mailman-web}
   notify:
     - reload mailman
     - restart mailman-web
@@ -46,7 +46,7 @@
   become_method: su
 
 - name: run Django management tasks
-  command: django-admin {{ item }} --pythonpath /etc/mailman3 --settings settings
+  command: django-admin {{ item }} --pythonpath /etc/webapps/mailman-web --settings settings
   loop:
     - migrate
     - loaddata