QPID-5560: Fix ReplicationTests.test_reject to work with SWIG and native clients.

Catch more general LinkError rather than TargetCapacityExceeded which is only raised by native client.

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1585985 13f79535-47bb-0310-9956-ffa450edef68