mod_include: The SSIAccessEnable directive existed to ensure the addition

of the "-A" syntax would not break existing configurations in v2.2. Remove
the directive for v2.4, defaulting the behaviour to enabled.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1204183 13f79535-47bb-0310-9956-ffa450edef68