Merge r1652982 from trunk:

Fix detection of old Solaris versions.
Autotools need double square brackets.

Submitted by: rjung
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1653963 13f79535-47bb-0310-9956-ffa450edef68