VMM/{,cli/}handler: Moved the 'address-in-use check' (introduced
with changeset ef99be5b7ec0) to {alias,relocated,user}_add().
# All parameters are described in pgsql_table(5) / PGSQL PARAMETERS
#
# The hosts that Postfix will try to connect to and query from.
hosts = localhost
# The user name and password to log into the pgsql server.
user = postfix
password = some_password
# The database name on the servers.
dbname = mailsys
# The SQL query template used to search the database
query = SELECT destination FROM postfix_relocated WHERE address='%s'