message: fix(ssh-tunnel): wrap pkey into StringIO buffer before creating the tunnel
diff: # under the License.
  import importlib
  +from io import StringIO
  from typing import TYPE_CHECKING
  from flask import Flask
  +from paramiko import RSAKey
  from sshtunnel import open_tunnel, SSHTunnelForwarder
  from superset.databases.utils import make_url_safe
  @@ -59,7 +61,9 @@ class SSHManager:
  if ssh_tunnel.password:
  params["ssh_password"] = ssh_tunnel.password
  elif ssh_tunnel.private_key:
  - params["private_key"] = ssh_tunnel.private_key
  + private_key_file = StringIO(ssh_tunnel.private_key)
  + private_key = RSAKey.from_private_key(private_key_file)
  + params["private_key"] = private_key
  params["private_key_password"] = ssh_tunnel.private_key_password
  return open_tunnel(**params)
  