[mailman3] Fix the ownership of log file

Both become and become_user needs to be set to work. So the script was executed
as root which caused the hyperkitty log file to be created with root owner.

Signed-off-by: Michal Konecny <mkonecny@redhat.com>

roles/mailman3/tasks/main.yml

@@ -301,6 +301,7 @@
     cmd: mailman-web migrate
     chdir: /etc/mailman3
   become_user: mailman
+  become: true
   tags:
     - mailman
     - db
@@ -341,6 +342,7 @@
     cmd: mailman-web collectstatic --no-input
     chdir: /etc/mailman3
   become_user: mailman
+  become: true
   tags:
     - mailman
     - hyperkitty
@@ -352,6 +354,7 @@
     cmd: mailman-web compress
     chdir: /etc/mailman3
   become_user: mailman
+  become: true
   tags:
     - mailman
     - hyperkitty