Enable environment variables for HTTP proxy

Author: daniele-athome

vdirsyncer/storage/dav.py

@@ -422,6 +422,7 @@ def _session(self):
         return aiohttp.ClientSession(
             connector=self.connector,
             connector_owner=False,
+            trust_env=True,
             # TODO use `raise_for_status=true`, though this needs traces first,
         )
 

vdirsyncer/storage/http.py

@@ -68,6 +68,7 @@ async def list(self):
         async with aiohttp.ClientSession(
             connector=self.connector,
             connector_owner=False,
+            trust_env=True,
             # TODO use `raise_for_status=true`, though this needs traces first,
         ) as session:
             r = await request(