Removed inaccurate sentence about PO files in translation docs.

.. admonition:: Mind your charset

    When creating a PO file with your favorite text editor, first edit

    the charset line (search for ``"CHARSET"``) and set it to the charset

    you'll be using to edit the content. Due to the way the ``gettext`` tools

    work internally and because we want to allow non-ASCII source strings in

    Django's core and your applications, you **must** use UTF-8 as the encoding

    for your PO file. This means that everybody will be using the same

    Due to the way the ``gettext`` tools work internally and because we want to

    allow non-ASCII source strings in Django's core and your applications, you

    **must** use UTF-8 as the encoding for your PO files (the default when PO

    files are created).  This means that everybody will be using the same

    encoding, which is important when Django processes the PO files.

To reexamine all source code and templates for new translation strings and