chore: fix reflection warning on javax.xml.parsers.SAXParser

[raszi]

Fixes the reflection warning that was introduced with #630.

There are only two different types that the library can pass to the javax.xml.parsers.SAXParser. It is either String or InputStream.

Unfortunately, I could not find a better way to fix the reflection warning just by refactoring the code a bit and have two explicit calls on the javax.xml.parsers.SAXParser/parse methods:

• https://docs.oracle.com/javase/8/docs/api/javax/xml/parsers/SAXParser.html#parse-java.lang.String-org.xml.sax.helpers.DefaultHandler-
• https://docs.oracle.com/javase/8/docs/api/javax/xml/parsers/SAXParser.html#parse-java.io.InputStream-org.xml.sax.helpers.DefaultHandler-