po: Update Polish program translations

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

debian/changelog

@@ -6,6 +6,7 @@ dpkg (1.17.14) UNRELEASED; urgency=low
 
   [ Updated programs translations ]
   * Czech (Miroslav Kure).
+  * Polish (Łukasz Dulny).
 
   [ Updated manpages translations ]
   * German (Helge Kreutzmann).