os-release: On Turris 1.0 factory parition has jffs2 filesystem not squashfs

This in effect means that modul turris_version doesn't fully work on Turris 1.0 unless users updated their factory images. It fails with error about invalid filesystem instead of printing factory system version.

Also there is different partitioning layout. On Turris 1.0 it wasn't partition 3 but 9.

We have to somehow detect which one of those two there is used and mount it accordingly.

related to #11