Fix FTBFS in parallel-tests with automake 1.13

(cherry picked from commit cc75733bc9)

cvs.sh

@@ -184,7 +184,7 @@ if egrep "^A[MC]_CONFIG_HEADER" configure.in >/dev/null 2>&1; then
   $AUTOHEADER || exit 1
   touch config.h.in
 fi
-$AUTOMAKE --foreign || exit 1
+$AUTOMAKE --add-missing --foreign || exit 1
 if test "$UNSERMAKE" = no; then
   echo "*** Postprocessing Makefile templates"
   perl -w admin/am_edit || exit 1