debian/copyright: Update copyright attributions.

debian/copyright

@@ -282,6 +282,7 @@ Files: .tx/config
        data/msd-locate-pointer.1
        data/mate-settings-daemon.1
        Makefile.am
+       makepot
        mate-settings-daemon/Makefile.am
        mate-settings-daemon/mate-settings-manager.xml
        plugins/a11y-keyboard/Makefile.am
@@ -355,7 +356,8 @@ License: GPL-2+ or LGPL-2.1+
 Comment:
  License(s) assumed from COPYING and COPYING.LIB files.
 
-Files: po/*.po
+Files: mate-settings-daemon.pot
+       po/*.po
        po/gnome-copyrights.txt
 Copyright:
  2003-2006, Miloslav Trmac <mitr@volny.cz>