channel-smartcard: Update due to spice-common cleanup
After commit 47e149705a5bb1d4a615facfd9bd0190d9b0647c (cfr "proto: Generate correct constants for smartcard support") msgc_smartcard_header was renamed to a more proper msgc_smartcard_data.
Signed-off-by: Frediano Ziglio fziglio@redhat.com