QPID: Additional transport NULL checks.
QPID: Additional transport NULL checks.

Addition of further NULL checks to the QPID transport code, to
address issues found via unit tests.

Signed-off-by: Damian Maguire <21930bd10afdadbc1f53edcd2634e8f66a5e6d7a@nyx.com>

MattMulhern/OpenMamaCassandra,cloudsmith-io/openmama,kuangtu/OpenMAMA,dpauls/OpenMAMA,cloudsmith-io/openmama,kuangtu/OpenMAMA,vulcanft/openmama,MattMulhern/OpenMamaCassandra,MattMulhern/OpenMamaCassandra,jacobraj/MAMA,vulcanft/openmama,fquinner/OpenMAMA,MattMulhern/OpenMAMA,MattMulhern/OpenMAMA,MattMulhern/OpenMAMA,vulcanft/openmama,cloudsmith-io/openmama,philippreston/OpenMAMA,dpauls/OpenMAMA,vulcanft/openmama,jacobraj/MAMA,dmaguire/OpenMAMA,dmaguire/OpenMAMA,philippreston/OpenMAMA,dmaguire/OpenMAMA,fquinner/OpenMAMA,vulcanft/openmama,fquinner/OpenMAMA,vulcanft/openmama,jacobraj/MAMA,philippreston/OpenMAMA,philippreston/OpenMAMA,kuangtu/OpenMAMA,dmagOM/OpenMAMA-dynamic,dmagOM/OpenMAMA-dynamic,dmaguire/OpenMAMA,cloudsmith-io/openmama,cloudsmith-io/openmama,dmagOM/OpenMAMA-dynamic,dmaguire/OpenMAMA,fquinner/OpenMAMA,MattMulhern/OpenMamaCassandra,jacobraj/MAMA,MattMulhern/OpenMAMA,MattMulhern/OpenMAMA,jacobraj/MAMA,kuangtu/OpenMAMA,dpauls/OpenMAMA,MattMulhern/OpenMamaCassandra,kuangtu/OpenMAMA,dmagOM/OpenMAMA-dynamic,philippreston/OpenMAMA,fquinner/OpenMAMA,cloudsmith-io/openmama,dpauls/OpenMAMA,jacobraj/MAMA,MattMulhern/OpenMamaCassandra,kuangtu/OpenMAMA,MattMulhern/OpenMAMA,fquinner/OpenMAMA,dpauls/OpenMAMA,kuangtu/OpenMAMA,dmagOM/OpenMAMA-dynamic,cloudsmith-io/openmama,MattMulhern/OpenMAMA,dmaguire/OpenMAMA,dpauls/OpenMAMA,philippreston/OpenMAMA,dpauls/OpenMAMA,dmaguire/OpenMAMA,vulcanft/openmama,dmagOM/OpenMAMA-dynamic,philippreston/OpenMAMA,fquinner/OpenMAMA