Update cnaf-annual-report-2018.tex

cnaf-annual-report-2018.tex

@@ -169,8 +169,9 @@ Introducing the sixth annual report of CNAF...
 \ia{The NA62 experiment at CERN}{na62}
 \ia{The NEWCHIM activity at CNAF for the CHIMERA and FARCOS devices}{newchim}
 \ia{The PADME experiment at INFN CNAF}{padme}
-%\ia{XENON computing activities}{xenon}
+\ia{XENON computing model}{xenon}
 \ia{Advanced Virgo computing at CNAF}{virgo}
+
 %
 % to keep together the next part title with its chapters in the toc
 %\addtocontents{toc}{\newpage}