Add missing GL_GENERATE_ARGZ_H conditional

- GL_GENERATE_ARGZ_H is used in gnulib/lib/Makefile.am

Upstream-Status: Pending
Signed-off-by: Constantin Musca <constantinx.musca@intel.com>

Index: augeas-1.0.0/configure.ac
===================================================================
--- augeas-1.0.0.orig/configure.ac
+++ augeas-1.0.0/configure.ac
@@ -55,6 +55,8 @@ AC_ARG_WITH([failmalloc],
 
 AM_CONDITIONAL([WITH_FAILMALLOC], [test x$with_failmalloc != xno])
 
+AM_CONDITIONAL([GL_GENERATE_ARGZ_H], [test -n "$ARGZ_H"])
+
 dnl --enable-debug=(yes|no)
 AC_ARG_ENABLE([debug],
               [AC_HELP_STRING([--enable-debug=no/yes],