Init the uninitialized member variable

Member 'IterativeParsingReaderHandler::Logs' is not initialized in the
constructor. Add its initialization.

test/unittest/readertest.cpp

@@ -1505,7 +1505,7 @@ struct IterativeParsingReaderHandler {
     uint32_t Logs[LogCapacity];
     size_t LogCount;
 
-    IterativeParsingReaderHandler() : LogCount(0) {
+    IterativeParsingReaderHandler() : Logs(0), LogCount(0) {
     }
 
     bool Null() { RAPIDJSON_ASSERT(LogCount < LogCapacity); Logs[LogCount++] = LOG_NULL; return true; }