Fix istioctl proxy-config link to not point at prelim docs (#1269)
Fix istioctl proxy-config link to not point at prelim docs (#1269)

Because that would be a dumb thing to do
geeknoid/istio.github.io,linsun/istio.github.io,ZackButcher/istio.github.io,geeknoid/istio.github.io,geeknoid/istio.github.io,ZackButcher/istio.github.io,linsun/istio.github.io,istio/istio.io,ZackButcher/istio.github.io,istio/istio.io,istio/istio.io,geeknoid/istio.github.io,istio/istio.io,istio/istio.io,istio/istio.io,linsun/istio.github.io,linsun/istio.github.io,linsun/istio.github.io,geeknoid/istio.github.io,ZackButcher/istio.github.io,istio/istio.io