Update Nginx configuration for new version of Nextcloud server >23 

Credentials save in MySQL installation

- Add credentials saving in mariadb cnf file

Fix Readme for apache TLS

As specified on
https://community.letsencrypt.org/t/apache-configuration-example/2338/4

The own certificate doesn't need to be included in the chain file.

Allow to use custom "php_ver" e.g. for PHP7.4 on Ubuntu 18.04 with ondrej PPA

untested!

Fix bash-ism 'and 'condition

should fix #103

Ansible is now on version 2.9

PHP 7.4 support for future Debian versions

removed some trailing whitespace

Package installs should not use latest

Only mysql has "default" in package name

Add option to set TLS cache size

Add indices after nextcloud is installed

fix empty test for nc apps

mysql: default-mysql-server
mariadb: mariadb-server

fixed ansible lint warning:
```
[403] Package installs should not use latest
```

[201] Trailing whitespace

7.4 is being used on my system and is recommended by Nextcloud.
So I feel like this may as well be added.

"php_version" to "php_ver" in README

*Fix* Debian does not have a "mysql-server" package

Removed my previous line and edited the install task to do a check for debian.

I changed ever place it said php_version to php_ver to accurately tell the user what variable is used in the playbook.

Spelling error fix

Disable the default site of apache and nginx on demand