kwargs and args must be preserved when MambuStruct.__init__ is called.

This impacts directly when reading a list MambuStruct (say, MambuLoans):
without the kwargs the new loans won't get configured according to the
params sent to the MambuStruct iterator.

So basically, the config done when calling the individual MambuStructs
in the list configuration changed ordering and now config is done before
disallowing for connection to Mambu (remember individual MambuStructs
from a list one do not reconnect to Mambu, they don't need to)