node tests: Report coverage url correctly.

This small patch accounts for our new
droplets dropping "zulipdev.org" from
the host name.

tools/test-js-with-node

@@ -189,8 +189,10 @@ def get_dev_host() -> str:
     user_id = os.getuid()
     user_name = pwd.getpwuid(user_id).pw_name
     if user_name == "zulipdev":
-        # For our droplets, we use the external hostname by default.
-        return os.uname()[1].lower() + ":9991"
+        hostname = os.uname()[1].lower()
+        if '.zulipdev.org' not in hostname:
+            hostname += '.zulipdev.org'
+        return hostname + ':9991'
     else:
         # For local development environments, we use localhost by
         # default, via the "zulipdev.com" hostname.