DISPATCH-1873: TCP echo test client prints errors to stderr
DISPATCH-1873: TCP echo test client prints errors to stderr

Fix applies only when run as main.

ganeshmurthy/qpid-dispatch,ganeshmurthy/qpid-dispatch,ted-ross/qpid-dispatch,ChugR/qpid-dispatch,mgoulish/qpid-dispatch,ErnieAllen/qpid-dispatch,mgoulish/qpid-dispatch,kgiusti/dispatch,ChugR/qpid-dispatch,ErnieAllen/qpid-dispatch,mgoulish/qpid-dispatch,ganeshmurthy/qpid-dispatch,apache/qpid-dispatch,apache/dispatch,apache/qpid-dispatch,apache/dispatch,ted-ross/qpid-dispatch,ChugR/qpid-dispatch,ErnieAllen/qpid-dispatch,ChugR/qpid-dispatch,ErnieAllen/qpid-dispatch,ted-ross/qpid-dispatch,apache/dispatch,apache/qpid-dispatch,kgiusti/dispatch,apache/qpid-dispatch,ganeshmurthy/qpid-dispatch,apache/dispatch,apache/qpid-dispatch,ganeshmurthy/qpid-dispatch,ChugR/qpid-dispatch,mgoulish/qpid-dispatch,kgiusti/dispatch,mgoulish/qpid-dispatch,ChugR/qpid-dispatch,apache/dispatch,kgiusti/dispatch,ted-ross/qpid-dispatch,kgiusti/dispatch,mgoulish/qpid-dispatch,ErnieAllen/qpid-dispatch,ganeshmurthy/qpid-dispatch,apache/dispatch,ErnieAllen/qpid-dispatch,ted-ross/qpid-dispatch,kgiusti/dispatch,ted-ross/qpid-dispatch,apache/qpid-dispatch,apache/dispatch