zeromq: bump to version 4.1.2

zeromq: bump to version 4.1.2

In the upstream git://github.com/zeromq/libzmq.git:

commit 6fdafc458a776e063511bb83dc7791aabea00b05 obviated the need for
0001-tests-disable-test_fork-if-fork-is-not-available.patch .

commit c8ee16940fff19ae3c12b4596c4bd131b2c71996 obviated the need for
0004-allow-without-libsodium.patch .

Fixed AUTORECONF comment in zeromq.mk to refer to the correct patch,
0001-acinclude.m4-make-kernel-specific-flags-cacheable.patch

Signed-off-by: Jonathan Ben Avraham <yba@tkos.co.il>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>