Reinstate a check that was presumably disabled because it wasn't
checking for the right expected date. At present pressing Enter in a
QDateTimeEdit without changing the date still emits the dataChanged()
signal. By reinstating the test, we ensure that the behaviour can't
change by accident.
Change-Id: I1b766af6ced001a4191606247338dbc91049cb8d
Reviewed-by: Rohan McGovern <rohan.mcgovern@nokia.com>