[PLS1.0] i18n comment: Add lang="it"

Comment from the i18n review of:
http://www.w3.org/TR/2006/WD-pronunciation-lexicon-20060131/

Comment 9
At http://www.w3.org/International/reviews/0603-pls10/
Editorial/substantive: E
Owner: RI
Location in reviewed document:
1.1, example

Comment:
 
We expected an xml:lang attribute around the phrase "La vita e' bella".