scripts/release: fix docker push command

Signed-off-by: Gyuho Lee <leegyuho@amazon.com>

scripts/release

@@ -185,7 +185,7 @@ main() {
     docker push "quay.io/coreos/etcd:${RELEASE_VERSION}"
 
     echo "Pushing container images to gcr.io ${RELEASE_VERSION}"
-    gcloud docker -- "push gcr.io/etcd-development/etcd:${RELEASE_VERSION}"
+    gcloud docker -- push "gcr.io/etcd-development/etcd:${RELEASE_VERSION}"
 
     for TARGET_ARCH in "-arm64" "-ppc64le"; do
       echo "Pushing container images to quay.io ${RELEASE_VERSION}${TARGET_ARCH}"