[C++] JoynrMessageSenderTest: Improve naming
[C++] JoynrMessageSenderTest: Improve naming

Change-Id: I7a541cd538f8af61b7d0bd92e1881eb34f7f56e1

bmwcarit/joynr,bmwcarit/joynr,clive-jevons/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,clive-jevons/joynr,bmwcarit/joynr,clive-jevons/joynr,clive-jevons/joynr,bmwcarit/joynr,clive-jevons/joynr,bmwcarit/joynr,bmwcarit/joynr,clive-jevons/joynr