package/iptuils: bump version to 3a86a2542c6fe29413c439bebeae11ec8a57ec7c

Remove 0001-ping-link-against-libm.patch as this has been fixed upstream.
See https://github.com/iputils/iputils/pull/42 and
https://github.com/iputils/iputils/commit/a5ddb78



Signed-off-by: Martin Bark <martin@barkynet.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>