[3.17] main/libssh2: upgrade to 1.11.0 & patch CVE-2023-48795
https://github.com/libssh2/libssh2/releases/tag/libssh2-1.11.0
https://github.com/libssh2/libssh2/commit/d34d9258b8420b19ec3f97b4cc5bf7aa7d98e35a
update source URL to https
enable basic tests
Edited by omni