The `to_nice_yaml` helper will by default wrap any string YAML values on
the first space after column 80. This can in worst case yield invalid
YAML syntax. More details in Ansible's documentation here:

https://docs.ansible.com/ansible/latest/user_guide/playbooks_filters.html#formatting-data-yaml-and-json

In short, you need to explicitly provide a custom width argument of a
high number of some kind to avoid the line wrapping.

Until now, we were leaving services "enabled"
(symlinks in /etc/systemd/system/multi-user.target.wants/).

We clean these up now. Broken symlinks may still exist in older
installations that enabled/disabled services. We're not taking care
to fix these up. It's just a cosmetic defect anyway.

All of `setup_install.yml` only runs if `matrix_bot_matrix_reminder_bot_enabled`,
so it's not necessary to add that condition once again.

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/887

We'll be adding `.timer` units later on, so it's good to be
more explicit.

This has been tested and appears to work.