You can ignore the error, and the code will still work. It seems like beem is smart enough to remember which API node is stable.

Or, you can force beem to use your favorite node like this:

API_NODE = 'https://api.deathwing.me'
HIVE = beem.Hive(node=[API_NODE])
beem.instance.set_shared_blockchain_instance(HIVE)

Then try the get_follow_count() call again.

Hope this helps!