Only upload node with gsutil in update_node.py if --upload is passed. (#1472)

This allows running the script locally.

Is there some kind of automated script that needs a matching update, or
was this always run manually?

scripts/update_node.py

diff --git a/scripts/update_node.py b/scripts/update_node.py
index b16d3e5..6080900 100755
--- a/scripts/update_node.py
+++ b/scripts/update_node.py
@@ -13,6 +13,7 @@
 
 import urllib.request
 import subprocess
+import sys
 import os
 import shutil
 
@@ -46,9 +47,10 @@
       subprocess.check_call(['zip', '-rq', filename, dirname])
       shutil.rmtree(dirname)
 
-    upload_url = upload_base + filename
-    print('Uploading: ' + upload_url)
-    cmd = ['gsutil', 'cp', '-n', filename, upload_url]
-    print(' '.join(cmd))
-    subprocess.check_call(cmd)
-    os.remove(filename)
+    if '--upload' in sys.argv:
+      upload_url = upload_base + filename
+      print('Uploading: ' + upload_url)
+      cmd = ['gsutil', 'cp', '-n', filename, upload_url]
+      print(' '.join(cmd))
+      subprocess.check_call(cmd)
+      os.remove(filename)