bug: SSL certification error when validating a URL

[emmambd]

What problem is your feature request trying to solve?

The add-new-updated-feeds GitHub workflow checks evaluates whether a GTFS feed can be downloaded. However, this check fails with the error: requests.exceptions.SSLError: HTTPSConnectionPool(host='gtfs.mot.gov.il', port=443): Max retries exceeded with url: (Caused by SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate')))

Even though the URL can be accessed and downloaded manually via a web browser, Python’s requests library fails due to missing intermediate certificates in the server’s SSL chain. This issue blocks the ability to add new sources.

examples where this affects GTFS feed downloads:

https://daten.transparenz.hamburg.de/Dataport.HmbTG.ZS.Webservice.GetRessource100/GetRessource100.svc/dbe5f144-b806-4377-aac3-d3572b139b23/Upload__hvv_Rohdaten_GTFS_Fpl_20250108.ZIP

https://gtfs.mot.gov.il/gtfsfiles/israel-public-transportation.zip

Solution
Provide a fallback mechanism to allow downloads when certificate verification fails.