Build problem IBAN/mandate not initialized

[janrosendahl]

In DirectDebit.java the static final variables IBAN and mandate have
to be initialized in the default constructor, otherwise build stops with
error (Variable 'IBAN'/.. might not have been initialized..)

/**
* bean constructor
*/
public DirectDebit() {
  this.IBAN = "";        // added to fix not inititalized
  this.mandate = ""; // added to fix not inititalized
}