Expose CURLOPT_HTTP09_ALLOWED

[jbangelo]

The CURLOPT_HTTP09_ALLOWED option tells curl to accept HTTP/0.9 responses, which can be a response just a body and no headers. This option has been disabled by default starting in v7.66 of curl, though some use cases still require it to be enabled.

[sagebind]

This is now published in the 0.4.44 release.