database_manager: Sets is_dirty=True conditionally
Sets is_dirty to True only when the password does not coincide with the one already in the safe.
Fixes: https://gitlab.gnome.org/World/PasswordSafe/-/issues/237
Sets is_dirty to True only when the password does not coincide with the one already in the safe.
Fixes: https://gitlab.gnome.org/World/PasswordSafe/-/issues/237