Socket auth

[stAn47]

Hello, it would be really great if automysqlbackup supports socket authentication.

Main mods which are needed are:

• if password is empty do not add --password to the command line (i'd prefer skipping whole authentication such as --user, --password ) if user is empty as well
• if host is exactly "localhost" and port is empty or default, then do not add "--port" (currently works when setting port as empty string)

On mariadb 10.4 :
CREATE USER 'myuser'@'localhost'
IDENTIFIED VIA unix_socket
OR mysql_native_password USING PASSWORD('mypassword');

Best regards, Stan