Revert "merged fix from Guillem Salas for bug https://issues.scala-lang.org/browse/SI-4267"

This reverts commit 2de8a3b4c6fadd3da0db7250fc2b7c8eaf95a9f5.
SI-4267 -  XMLEventReader Parser thread don't swallow IO/Parse exceptions anymore
SI-4267 - Threading in XMLEventReader swallows IO/Parse exceptions fix + temporary workaround to https://github.com/scala/scala-xml/issues/20