Small change to r952007, ensure we don't wipe out the $enable_foomod value

when that value is 'shared'. The 'yes', 'shared', 'static' and 'no' values
are all valid.



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1750553 13f79535-47bb-0310-9956-ffa450edef68