deb: 50-server.cnf:collation-server = utf8mb4_general_ci dated- replace with utf8mb4_uca1400_ai_ci

Wordpress moved to utf8mb4_unicode_ci / utf8mb4_unicode_520_ci where available and left the utf8mb4_general_ci behind. It seems odd that the default server-collation is utf8mb4_general_ci.

Now that we have uc1400 we should use this in new installations.

will need updating: https://mariadb.com/kb/en/differences-in-mariadb-in-debian-and-ubuntu/