SECURITY (CVE-2012-0031): Fix possible crash on shutdown if a child

SECURITY (CVE-2012-0031): Fix possible crash on shutdown if a child
changes the sb_type field in the scoreboard.  Since unprivileged
children should not be able to affect the parent in this way, this is
treated as a Low severity security issue.

Thanks to "halfdog" <me halfdog.net> for reporting this issue.

* include/scoreboard.h (global_score): Remove sb_type field.

* include/ap_mmn.h: Bump MMN for above.

* server/scoreboard.c (ap_cleanup_scoreboard, ap_create_scoreboard):
  Use a static global to store store the scoreboard type.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1230065 13f79535-47bb-0310-9956-ffa450edef68