Revert "nixos/nextcloud: temp fix for MariaDB >=10.6"

This reverts commit f182b8d23b.

This doesn't need to be on 21.05, because 21.05 doesn't have MariaDB
10.6.

It shouldn't be on 21.05 because the package version warning mentions
21.11, which is confusing and misleading.

nixos/tests/nextcloud/with-mysql-and-memcached.nix

@@ -42,13 +42,6 @@ in {
         enable = true;
         bind = "127.0.0.1";
         package = pkgs.mariadb;
-
-        # FIXME(@Ma27) Nextcloud isn't compatible with mariadb 10.6,
-        # this is a workaround.
-        # See https://help.nextcloud.com/t/update-to-next-cloud-21-0-2-has-get-an-error/117028/22
-        extraOptions = ''
-          innodb_read_only_compressed=0
-        '';
         initialScript = pkgs.writeText "mysql-init" ''
           CREATE USER 'nextcloud'@'localhost' IDENTIFIED BY 'hunter2';
           CREATE DATABASE IF NOT EXISTS nextcloud;