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