4.4.0-1013.22) is not available, but a newer one is (4.4.0-1017.26). We redirected you there.
/usr/share/isenkram/Fw-Contents-powerpc-sid-contrib is in isenkram-cli 0.22.
This file is owned by root:root, with mode 0o644.
It is a symlink to /usr/share/isenkram/./usr/share/isenkram/Fw-Contents-amd64-sid-contrib