Check index file's endianess earlier, otherwise we'll complain about other problems.
Check index file's endianess earlier, otherwise we'll complain about other
problems.

--HG--
branch : HEAD

dscho/dovecot,jkerihuel/dovecot,dscho/dovecot,jkerihuel/dovecot,jwm/dovecot-notmuch,jwm/dovecot-notmuch,jwm/dovecot-notmuch,jwm/dovecot-notmuch,dscho/dovecot,jwm/dovecot-notmuch,dscho/dovecot,jkerihuel/dovecot,jkerihuel/dovecot,jkerihuel/dovecot,dscho/dovecot