fix missing iterator increment (#2331)

Thank you @bradhowes (#2181)

Author: richardeakin

src/cinder/audio/Param.cpp

@@ -352,6 +352,7 @@ void Param::removeEventsAt( double time )
 		if( event.getTimeBegin() >= time ) {
 			if( contextDisabled ) {
 				eventIt = mEvents.erase( eventIt );
+				++eventIt;
 			}
 			else {
 				event.cancel();