* https over socks fix: fix issue with https url handling by using 'adapter.proxy_manager_for()' instead of 'adapter.get_connection' to get proxy manager, which create connection indirectly (parallel to no-proxy path).
- simplify socks config, avoiding global monkey-patch, as requests/urllib3 now support socks proxy directly and do not require patching global socket.
- add SOCKS_DISABLE env dynamically disabling socks proxy