Cannot edit DSN of database adapters

When editing an existing database adapter, that contains data in the DSN-field, you cannot save it. 
A response of:
{"type":"http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html","title":"Bad Request","status":400,"detail":"Unrecognized field \"dsn\""} 
is returned.

Creating a new adapter, with data in DSN works as expected.