package/sconeserver: fix build with gcc-6

We simply bump the version rather than backport the patch, as there has
been only very few, minor commits in-between.

Fixes:
    http://autobuild.buildroot.org/results/fa7/fa7881c6ffb821a2aff139f95ba53c96d6e2b942/
    http://autobuild.buildroot.org/results/749/749fbd6cc505f6f3c0cccfeb63be6deddab8fba5/



Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>