translatewiki-issues

received an email with two translatewiki issues:

* https://translatewiki.net/wiki/Thread:Support/About_MediaWiki:Gwtoolset-no-xml-element-found/en
  i have adjusted the parametes and code for Gwtoolset-no-xml-element-found; hopefully that will
  help with translation

* https://translatewiki.net/wiki/Thread:Support/About_MediaWiki:Gwtoolset-mediafile-throttle/en
  we want to keep the term throttle over the term threshold. i did re-write the copy for
  Gwtoolset-mediafile-throttle-description, which will hopefully make its use clearer.

Change-Id: Ibd4f4089a92de73d3bcc85814c84f959ef91949e