Fix outdated Kourier url (#587)

Author: seb-goodman

hack/build-flags.sh

@@ -27,7 +27,7 @@ function build_flags() {
   # Knative component versions
   local branch="`git branch --show-current | cut -d '-' -s -f2`"
   local serving="`git ls-remote --tags --ref https://github.com/knative/serving.git | grep -F "${branch}" | cut -d '-' -f2 | cut -d 'v' -f2 | sort -Vr | head -n 1`"
-  local kourier="`git ls-remote --tags --ref https://github.com/knative-sandbox/net-kourier.git | grep -F "${branch}" | cut -d '-' -f2 | cut -d 'v' -f2 | sort -Vr | head -n 1`"
+  local kourier="`git ls-remote --tags --ref https://github.com/knative-extensions/net-kourier.git | grep -F "${branch}" | cut -d '-' -f2 | cut -d 'v' -f2 | sort -Vr | head -n 1`"
   local eventing="`git ls-remote --tags --ref https://github.com/knative/eventing.git | grep -F "${branch}" | cut -d '-' -f2 | cut -d 'v' -f2 | sort -Vr | head -n 1`"