proper quoting / make zsh happy (#350)
proper quoting / make zsh happy (#350)

fixes https://github.com/istio/issues/issues/12 until we get rid of GATEWAY_URL altogether
jasminejaksic/istio.github.io,geeknoid/istio.github.io,istio/istio.io,ZackButcher/istio.github.io,smawson/istio.github.io,ZackButcher/istio.github.io,linsun/istio.github.io,jasminejaksic/istio.github.io,smawson/istio.github.io,geeknoid/istio.github.io,istio/istio.io,ZackButcher/istio.github.io,geeknoid/istio.github.io,jasminejaksic/istio.github.io,smawson/istio.github.io,jasminejaksic/istio.github.io,ZackButcher/istio.github.io,linsun/istio.github.io,istio/istio.io,mandarjog/mandarjog.github.io,mandarjog/mandarjog.github.io,istio/istio.io,mandarjog/mandarjog.github.io,linsun/istio.github.io,istio/istio.io,geeknoid/istio.github.io,mandarjog/mandarjog.github.io,istio/istio.io,geeknoid/istio.github.io,linsun/istio.github.io,linsun/istio.github.io,smawson/istio.github.io,istio/istio.io