Fix autotools/check-header
Fix autotools/check-header

86def278 tried to fix check-header for Python 3 unsuccesfully using a
search-and-replace method, which didn't work as next(zip) is not
callable.

Signed-off-by: Apollon Oikonomopoulos <ed81ed0a45ccd5c8869bda52e38353a6299ee39e@dmesg.gr>

mbakke/ganeti,ganeti/ganeti,mbakke/ganeti,mbakke/ganeti,ganeti/ganeti,ganeti/ganeti