build-sys: drop AM_GNU_GETTEXT as it fights with IT_PROG_INTLTOOL

build-sys: drop AM_GNU_GETTEXT as it fights with IT_PROG_INTLTOOL

  <mbiebl> kay, mezcalero: https://bugzilla.gnome.org/show_bug.cgi?id=627789
  <mezcalero> so we can drop that entirely?
  <mezcalero> kay: if you drop those two lines, does it improve things for you?
  <mbiebl> kay: but ./configure should work now
  <mbiebl> resp. autogen.sh
  <kay> mezcalero, mbiebl: autogen.sh seems a lot better without the two lines
  <kay> mezcalero: works without the 'touch' thing
  <mezcalero> kay: ok, commit please