lftp does not support https protocol on x86_64:
vetter@beder:~> lftp https://user@you.novell.com/update
/usr/lib64/lftp/3.2.1/proto-https.so: cannot open shared object file: No such file or directory
lftp: https - not supported protocol

It works in 9.2 i586.

Problem guess: lftp is not compiled with openssl library:
10.0:~> ldd /usr/lib64/lftp/3.2.1/proto-http.so
        liblftp-network.so => /usr/lib64/lftp/3.2.1//liblftp-network.so (0x00002aaaaabe3000)
        libutil.so.1 => /lib64/libutil.so.1 (0x00002aaaaad4c000)
        libncurses.so.5 => /lib64/libncurses.so.5 (0x00002aaaaae4f000)
        libdl.so.2 => /lib64/libdl.so.2 (0x00002aaaaafb3000)
        libc.so.6 => /lib64/tls/libc.so.6 (0x00002aaaab0b6000)
        libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00002aaaab2e1000)
        /lib64/ld-linux-x86-64.so.2 (0x0000555555554000)

Whereas in 9.2 i586 you get:
9.2:~> ldd /usr/lib/lftp/3.0.6/proto-http.so
        linux-gate.so.1 =>  (0xffffe000)
        liblftp-network.so => /usr/lib/lftp/3.0.6/liblftp-network.so (0xb7fb9000)
        libutil.so.1 => /lib/libutil.so.1 (0xb7f83000)
        libncurses.so.5 => /lib/libncurses.so.5 (0xb7f3e000)
        libresolv.so.2 => /lib/libresolv.so.2 (0xb7f2b000)
        libdl.so.2 => /lib/libdl.so.2 (0xb7f27000)
        libm.so.6 => /lib/tls/libm.so.6 (0xb7f04000)
        libc.so.6 => /lib/tls/libc.so.6 (0xb7ded000)
        libgcc_s.so.1 => /lib/libgcc_s.so.1 (0xb7de5000)
        libssl.so.0.9.7 => /usr/lib/libssl.so.0.9.7 (0xb7db5000)
        libcrypto.so.0.9.7 => /usr/lib/libcrypto.so.0.9.7 (0xb7cc4000)
        /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x80000000)