Fix assumed return type of MSVC

Wenfeng CAI

2018-11-13 a0b74b09a5824d50613e3b3a5590e7a9ed515716

 src/library/base/EventRegistry.cpp

@@ -79,7 +79,7 @@
}

void EventRegistry::addError(EVENT_TYPE event) {
   addEvent(event, SVRT_ERROR);
   this->addEvent(event, SVRT_ERROR);
}

void EventRegistry::addEvent(EVENT_TYPE event, SEVERITY severity) {