Don't use a linkmap to cut down the exported library symbols if
the compiler if gcc 4.1.2 (as used in RHEL 5). This fixes a crash
in the unit tests somehow triggered by adding the work in QPID-5415.

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1557946 13f79535-47bb-0310-9956-ffa450edef68