Fix no_proxy reset in configuration.py

This commit removes the redundant assignment to `None`, ensuring that the `no_proxy` environment variable is preserved and proxy bypass settings are applied as expected.

Author: daezaa

kubernetes/client/configuration.py

@@ -170,7 +170,6 @@ def __init__(self, host="http://localhost",
  if os.getenv("no_proxy"): self.no_proxy = os.getenv("no_proxy")
  """Proxy URL
  """
- self.no_proxy = None
  """bypass proxy for host in the no_proxy list.
  """
  self.proxy_headers = None