Normalised database with one-to-one relationship
The attributes should be split in 2 tables because the configuration details are not depending on the user but on the configuration of an external system. If a user can have only 1 configuration then you must use an 1-1 relation. If a user can have multiple configurations then you must use the 1-M relation.

This is the theory. If you want (in case of a 1-1 relation) put all in 1 table than this is also 'allowed'. Remember well that if one day the relation becomes 1-M that you are in problems. This is also why it is preferred to split the information into 2 tables.