Add replace directive to prevent contacting istio.io during the… (#7194)

They keep having TLS handshake timeouts. Its pointed at github instead.

go.mod

@@ -84,3 +84,5 @@ require (
 	k8s.io/apimachinery v0.0.0-20190223001710-c182ff3b9841
 	k8s.io/client-go v8.0.0+incompatible
 )
+
+replace istio.io/gogo-genproto v0.0.0-20190124151557-6d926a6e6feb => github.com/istio/gogo-genproto v0.0.0-20190124151557-6d926a6e6feb

go.sum

@@ -212,6 +212,7 @@ github.com/hpcloud/tail v1.0.0 h1:nfCOvKYfkgYP8hkirhJocXT2+zOD8yUNjXaWfTlyFKI=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
 github.com/imdario/mergo v0.3.6 h1:xTNEAn+kxVO7dTZGu0CegyqKZmoWFI0rF8UxjlB2d28=
 github.com/imdario/mergo v0.3.6/go.mod h1:2EnlNZ0deacrJVfApfmtdGgDfMuh/nq6Ok1EcJh5FfA=
+github.com/istio/gogo-genproto v0.0.0-20190124151557-6d926a6e6feb/go.mod h1:mvv8vRzGSduueppJLi6LhwN+hLFo0GeXquj6ixCv5xk=
 github.com/jarcoal/httpmock v0.0.0-20180424175123-9c70cfe4a1da h1:FjHUJJ7oBW4G/9j1KzlHaXL09LyMVM9rupS39lncbXk=
 github.com/jarcoal/httpmock v0.0.0-20180424175123-9c70cfe4a1da/go.mod h1:ks+b9deReOc7jgqp+e7LuFiCBH6Rm5hL32cLcEAArb4=
 github.com/jmespath/go-jmespath v0.0.0-20180206201540-c2b33e8439af h1:pmfjZENx5imkbgOkpRUYLnmbU7UEFbjtDA2hxJ1ichM=