Revert "Only update packages indexes if the cache is 1 hour old"

This reverts commit 201165cff662caad9b51508272e7f8f2eece7b0c.

Turns out this actually breaks initial deployments, because the
cache gets updated in the first task, then you add sources for
nginx and mariadb, but it doesn't update the indexes because the
cache is < 3600 seconds old, so you end up getting the distro's
versions of nginx and mariadb.

roles/mariadb/tasks/main.yml

@@ -15,7 +15,7 @@
   tags: mariadb, packages
 
 - name: Install mariadb-server
-  apt: name={{ item }} state=present update_cache=yes cache_valid_time=3600
+  apt: name={{ item }} state=present update_cache=yes
   with_items:
     - mariadb-server
     - python-mysqldb # for ansible