[common] add 'proxy-env' option

(#6134, #6455)
disable using environment proxies by default

docs/configuration.rst

@@ -600,10 +600,22 @@ Description
       ``scheme://host`` as key.
       See `Requests' proxy documentation`_ for more details.
 
-    Note: If a proxy URLs does not include a scheme,
+    Note: If a proxy URL does not include a scheme,
     ``http://`` is assumed.
 
 
+extractor.*.proxy-env
+---------------------
+Type
+    ``bool``
+Default
+    ``false``
+Description
+    Collect proxy configuration information from environment variables
+    (``HTTP_PROXY``, ``HTTPS_PROXY``, ``NO_PROXY``)
+    and Windows Registry settings.
+
+
 extractor.*.source-address
 --------------------------
 Type

gallery_dl/extractor/common.py

@@ -345,6 +345,9 @@ class Extractor():
         headers.clear()
         ssl_options = ssl_ciphers = 0
 
+        # .netrc Authorization headers are alwsays disabled
+        session.trust_env = True if self.config("proxy-env", False) else False
+
         browser = self.config("browser")
         if browser is None:
             browser = self.browser