Fix SIGSEGV on some systems because the Vary fixup included

a call to table_do with a variable argument list that was not
NULL terminated.  Other optimizations will follow.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@83543 13f79535-47bb-0310-9956-ffa450edef68