[Bug] alternc.install réinit client of db_servers

[sachaz]

I used alternc.install and noticed that it update db_servers set client='%' instead of the localhost I had.

Default value of client in db_server was localhost, alternc.install changed it for "%" which is should not be a default value, mariadb listens on 127.0.0.1

Furthermore this change makes all new db users unable to connect.