network: fix password window popup issue when editing connections

This is a temporary solution, the right way is to
dispatch password through keyring or similar service.

tower: https://tower.im/projects/15081ba156b14fa4bd6d9e82f91edff3/todos/f91933b438b3452cad081b958c9530b2/
Change-Id: I5569cad248e0c0638294246d2c6bb1b4188cf953