Bug #5329 : multilingual - fixing the case of adding a first WYSIWYG content to a publication that the content language is not the same as the one selected at application level.

The language of the WYSIWYG content used was the one selected at application level instead of the one of the publication ...

Please don't forget to check https://github.com/Silverpeas/Silverpeas-Core/pull/507 PR.