docs: correct error in 'merge_environment_settings' usage
Resolves
@@ -203,7 +203,7 @@ You can get around this behaviour by explicity merging the environment settings
prepped = s.prepare_request(req)
# Merge environment settings into session
- settings = s.merge_environment_settings(prepped.url, None, None, None, None)
+ settings = s.merge_environment_settings(prepped.url, {}, None, None, None)
resp = s.send(prepped, **settings)
print(resp.status_code)
