Fix unintended fallthrough

Change-Id: Ie67e0f5b41886d1c1b20f61bcd9fb7abc5f903bf
Reviewed-on: https://codereview.kdab.com/47834
Tested-by: Continuous Integration <build@kdab.com>
Reviewed-by: Frank Osterfeld <frank.osterfeld@kdab.com>

Charm/Widgets/ActivityReport.cpp

@@ -509,6 +509,7 @@ void ActivityReport::slotLinkClicked(const QUrl &which)
         m_properties.end = which.toString()
                            == QLatin1String("Previous") ? m_properties.end.addMonths(-1)
                            : m_properties.end.addMonths(1);
+        break;
     case Year:
         m_properties.start = which.toString()
                              == QLatin1String("Previous") ? m_properties.start.addYears(-1)