Prefer global instead link-local iface addr
Prefer global instead link-local iface addr

Some environments may assign multiple IP addresses
on a single interface. It's better to use a global
address to a link-local one (which was probably used
for bootstrapping).

Fixes #73

ingvagabund/flannel,dcbw/flannel,jonboulle/flannel,MohdAhmad/flannel,coreos/flannel,endocode/flannel,EverythingMe/flannel,MohdAhmad/flannel,MohdAhmad/flannel,dcbw/flannel,wikimedia/operations-debs-flannel,adiclepcea/flannel,coreos/flannel,ingvagabund/flannel,bprashanth/flannel,endocode/flannel,svdata/flannel,cusspvz/flannel,kelcecil/flannel,wikimedia/operations-debs-flannel,flynn/flannel,cusspvz/flannel,coreos/flannel,eyakubovich/flannel,benbjohnson/flannel,cusspvz/flannel,lvlv/flannel,endocode/flannel,benbjohnson/flannel,EverythingMe/flannel,lihuanghai/flannel,lvlv/flannel,kelcecil/flannel,ingvagabund/flannel,adiclepcea/flannel,sujitfulse/flannel,eyakubovich/flannel,eyakubovich/flannel,Yhgenomics/flannel,svdata/flannel,EverythingMe/flannel,Yhgenomics/flannel,imzhulei/flannel,wikimedia/operations-debs-flannel,benbjohnson/flannel,jonboulle/flannel,bprashanth/flannel,bprashanth/flannel,lihuanghai/flannel,flynn/flannel,adiclepcea/flannel,lihuanghai/flannel,lvlv/flannel,jonboulle/flannel,sujitfulse/flannel,dcbw/flannel,svdata/flannel,imzhulei/flannel,sujitfulse/flannel,Yhgenomics/flannel,flynn/flannel,imzhulei/flannel,kelcecil/flannel