po: Update Italian man pages translation

[guillem@debian.org:
 - Fix POD markup. ]

Closes: #771673
Signed-off-by: Guillem Jover <guillem@debian.org>

debian/changelog

@@ -12,6 +12,9 @@ dpkg (1.17.23) UNRELEASED; urgency=low
   * Polish (Łukasz Dulny).
   * Russian (Yuri Kozlov). Closes: #772841
 
+  [ Updated manpages translations ]
+  * Italian (Beatrice Torracca). Closes: #771673
+
   [ Updated dselect translations ]
   * Czech (Miroslav Kure).
   * Polish (Łukasz Dulny).