use same configuration directives as the registry

conf/manager.conf.in

@@ -27,7 +27,7 @@ level = info
 type = mysql
 host = localhost
 name = idp_account_manager
-user = idpadmin
+username = idpadmin
 password = secret
 
 [idp]

lib/AccountManager/App.pm

@@ -54,11 +54,11 @@ sub new {
     $self->{logger} = Log::Any->get_logger();
 
     AccountManager::DB->register_db(
-        driver          => $self->{configuration}->{database}->{type},
-        database        => $self->{configuration}->{database}->{name},
-        host            => $self->{configuration}->{database}->{host},
-        password        => $self->{configuration}->{database}->{password},
-        username        => $self->{configuration}->{database}->{user}
+        driver   => $self->{configuration}->{database}->{type},
+        database => $self->{configuration}->{database}->{name},
+        host     => $self->{configuration}->{database}->{host},
+        username => $self->{configuration}->{database}->{username},
+        password => $self->{configuration}->{database}->{password},
     );
 
     $self->{db} = AccountManager::DB->new();