Change the assigned default credential on account creation
If you are using self registration, and you want to assign a different credential on account creation you need to update the CREDENTIALS table.
You can only assign one default so you must set the original default to 0 then update the credential you choose with a 1 in the USEASDEFAULT field.
UPDATE CREDENTIALS SET USEASDEFAULT=0 WHERE ID='1';
UPDATE CREDENTIALS SET USEASDEFAULT=1 WHERE ID='2';
After this change you will need to restart your LUNA's tomcat.