ktap: bump version

We switch from a tag to a commit ID, because the last release is from
December 2013, even though many new changes have been made to ktap
since then (~80 commits). Ktap has had 4 releases in its history, all
made during the first 7 months of its existence, but then no more
releases have been made.

[Thomas: reword commit log, add patch to fix build with uClibc, remove
KTAP_SOURCE since we're fetching from github.]

Signed-off-by: Maxime Hadjinlian <maxime.hadjinlian@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>