Description:
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XMLReader::getParserProperty() throws ValueError when the instance is empty, while it should return false.

Test script:
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$reader = new XMLReader();
var_dump($reader->getParserProperty(XMLReader::LOADDTD));

Expected result:
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bool(false)

Actual result:
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Fatal error: Uncaught ValueError: XMLReader::getParserProperty(): Argument #1 ($property) must be a valid parser property in ...