BLISS: 1.11 fix image roi 0 0 0 0

Closes #3928 (closed)

In the branch 1.11, a new _cur_roi settings was added to sync this state with daiquiri.

_roi and _cur_roi are now supposed to be updated together at the same time

but it is not the case at the very first use of this new setting.

This PR make sure both attributes are initialized.