Fix to ensure no trailing slash in crn node url

[philogicae]

No description provided.

[github-actions]

Summary:

• The PR includes a small change to the node_url initialization to remove the trailing slash, which is a common practice to ensure consistency in URL formatting.
• This change is unlikely to introduce bugs and is a straightforward improvement to the codebase.

Highlighting relevant parts of the diff:

-        self.node_url = node_url
+        self.node_url = node_url.rstrip('/')

This change ensures that the node_url is consistently formatted without a trailing slash, which is a best practice for URL handling to avoid potential routing issues. The impact of this change is minimal and does not introduce any new functionality or substantial modifications to the existing logic.

[Psycojoker]

You can merge one you've run black on it for me