CLSA-2026-1774366569 Fix CVE(s): CVE-2026-3497

SECURITY UPDATE: pre-auth crash via GSSAPI key exchange - debian/patches/CVE-2026-3497.patch: replace sshpktdisconnect with sshpacketdisconnect and initialize gssbufferdesc variables in kexgssc.c, kexgsss.c. - CVE-2026-3497...