Update the clang format configuration to disable include sorting. This
is enabled by default and breaks samba code.

Signed-off-by: Gary Lockyer <gary@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

Autobuild-User(master): Gary Lockyer <gary@samba.org>
Autobuild-Date(master): Tue Jul 10 04:40:51 CEST 2018 on sn-devel-144