install-deps.sh: install binutils 2.28 for xenial

install-deps.sh: install binutils 2.28 for xenial

ld 2.26 segment faults when linking librados.so in
https://github.com/ceph/ceph/pull/16715 .

while ld 2.28 always survives.
binutils 2.28 is rebuilt and uploaded to chacra
binutils/master/7fa393306ed8b93019d225548474c0540b8928f7/ubuntu/xenial,

so let's use it instead.

the source deb package comes from
http://ppa.launchpad.net/jonathonf/binutils/ubuntu

i tried to use the binutils 2.30 source package from bionic,
but it has build dependency of dpkg-dev (>= 1.19.0.5) which cannot be
fulfilled on xenial. so without more changes, we cannot get
binutils 2.30 built on xenial using this source package.

Fixes: https://tracker.ceph.com/issues/42596
Signed-off-by: Kefu Chai <kchai@redhat.com>