Harness: Don't fail on utf-8 encoding
Harness: Don't fail on utf-8 encoding

The tag file of cscope may contain unicode characters, and
they show up when we want to do a git diff.

Signed-off-by: Lukas Humbel <075b23d3799996371316004d7c515be9b6f17b2b@inf.ethz.ch>

BarrelfishOS/barrelfish,kishoredbn/barrelfish,kishoredbn/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish,kishoredbn/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish,kishoredbn/barrelfish