It just make no sense to backup/restore the mysql password...

data/hooks/backup/11-conf_ynh_mysql

@@ -1,13 +0,0 @@
-#!/bin/bash
-
-# Exit hook on subcommand error or unset variable
-set -eu
-
-# Source YNH helpers
-source /usr/share/yunohost/helpers
-
-# Backup destination
-backup_dir="${1}/conf/ynh/mysql"
-
-# Save MySQL root password
-ynh_backup "/etc/yunohost/mysql" "${backup_dir}/root_pwd"

data/hooks/restore/11-conf_ynh_mysql

@@ -1,42 +0,0 @@
-backup_dir="$1/conf/ynh/mysql"
-MYSQL_PKG="$(dpkg --list | sed -ne 's/^ii  \(mariadb-server-[[:digit:].]\+\) .*$/\1/p')"
-
-. /usr/share/yunohost/helpers
-
-# ensure that mysql is running
-service mysql status >/dev/null 2>&1 \
-  || service mysql start
-
-# retrieve current and new password
-[ -f /etc/yunohost/mysql ] \
-  && curr_pwd=$(cat /etc/yunohost/mysql)
-new_pwd=$(cat "${backup_dir}/root_pwd" || cat "${backup_dir}/mysql")
-[ -z "$curr_pwd" ] && curr_pwd="yunohost"
-[ -z "$new_pwd" ] && {
-    new_pwd=$(ynh_string_random 10)
-}
-
-# attempt to change it
-mysqladmin -s -u root -p"$curr_pwd" password "$new_pwd" || {
-
-  echo "It seems that you have already configured MySQL." \
-    "YunoHost needs to have a root access to MySQL to runs its" \
-    "applications, and is going to reset the MySQL root password." \
-    "You can find this new password in /etc/yunohost/mysql." >&2
-
-  # set new password with debconf
-  debconf-set-selections << EOF
-$MYSQL_PKG mysql-server/root_password password $new_pwd
-$MYSQL_PKG mysql-server/root_password_again password $new_pwd
-EOF
-
-  # reconfigure Debian package
-  dpkg-reconfigure -freadline -u "$MYSQL_PKG" 2>&1
-}
-
-# store new root password
-echo "$new_pwd" | tee /etc/yunohost/mysql
-chmod 400 /etc/yunohost/mysql
-
-# reload the grant tables
-mysqladmin -s -u root -p"$new_pwd" reload