Clarify new header configuration syntax
Clarify new header configuration syntax

Make it clear that there are no spaces in the
new header section.

Change-Id: I69c14017820621a3aea75e41960ac3758f7e4835

openstack-dev/devstack,varunarya10/devstack,bswartz/devstack,bigswitch/devstack,nawawi/openstack,avvocatodemarchis/devstack,ozamiatin/devstack,Mahito/devstack,noironetworks/devstack,parul24/devstack,bswartz/devstack,dtroyer/devstack,vsham20/devstack,bigswitch/devstack,TwinkleChawla/devstack,costingalan/devstack,richliu/devstack,dirkmueller/devstack,group-policy/devstack,pombredanne/devstack,avvocatodemarchis/devstack,richliu/devstack,mc2014/devstack,olivierlemasle/devstack,dtroyer/devstack,nawawi/openstack,thomasem/devstack,prithivm/branch01,costingalan/devstack,ozamiatin/devstack,mssumanth/devstack,group-policy/devstack,samgoon/devstack,vsham20/devstack,Mahito/devstack,mssumanth/devstack,thomasem/devstack,varunarya10/devstack,TwinkleChawla/devstack,parul24/devstack,samgoon/devstack,mc2014/devstack,dirkmueller/devstack,pombredanne/devstack,openstack-dev/devstack,olivierlemasle/devstack,noironetworks/devstack,prithivm/branch01