d/control: Use metapackage instead of meta package

This makes lintian happy

debian/control

@@ -27,7 +27,7 @@ Depends:
  usb-modeswitch,
  usbutils,
  librem5-base-defaults (>= ${source:Version}),
-Description: Meta package for the Librem5
+Description: Metapackage for the Librem5
  This package contains base dependencies for the librem5
  .
  It should be installed on every librem5.
@@ -55,7 +55,7 @@ Depends:
  network-manager-gnome,
  xdg-desktop-portal-gtk,
  librem5-base,
-Description: GNOME meta package for the Librem5
+Description: GNOME metapackage for the Librem5
  This package contains the GNOME apps for the Librem5
  .
  It should be installed on every librem5.