MD5 fingerprint not available by default in libssh2 HEAD, test fails

[rainerjung]

libssh2 > 1.11.1 (current HEAD) introduces new build time defines that control, which crypto algorithms are enabled. Most of the optional ones will be disabled by default. See https://raw.githubusercontent.com/libssh2/libssh2/refs/heads/master/RELEASE-NOTES.

The ssh2 extension provides and uses the MD5 fingerprint functionality unconditionally. This will fail for the next libssh2 release, eg. in the unit test tests/ssh2_connect.phpt:

---- EXPECTED OUTPUT
**Connect
bool(true)
string(12) "SSH2 Session"
**Fingerprint MD5
bool(true)
int(32)
bool(true)
...
---- ACTUAL OUTPUT
**Connect
bool(true)
string(12) "SSH2 Session"
**Fingerprint MD5

Warning: ssh2_fingerprint(): Unable to retrieve fingerprint from specified session in /path/to/tests/ssh2_connect.php on line 9
bool(false)
int(0)

Deprecated: ctype_xdigit(): Argument of type bool will be interpreted as string in the future in /path/to/tests/ssh2_connect.php on line 12
bool(false)

I think there is currently no nice way to detect MD5 availability in libssh2. I opened libssh2/libssh2#2161 there.