ninja: don't bother building c-ares shared libraries
ninja: don't bother building c-ares shared libraries

c-ares's "configure" defaults to building both shared and static
libraries. We don't need the shared libraries, so let's not waste
time building them.

Signed-off-by: Nadav Har'El <625169824b719df98706d88646d0aae6f368ae4d@scylladb.com>
Message-Id: <20170202171928.5135-1-625169824b719df98706d88646d0aae6f368ae4d@scylladb.com>

avikivity/seastar,scylladb/seastar,avikivity/seastar,scylladb/seastar,avikivity/seastar,syuu1228/seastar,syuu1228/seastar,dreamsxin/seastar,cloudius-systems/seastar,scylladb/seastar,dreamsxin/seastar,dreamsxin/seastar,cloudius-systems/seastar,cloudius-systems/seastar,syuu1228/seastar