[gucharmap] configure: Add missing AC_ARG_VAR

[Florian MÃllner <fmuellner src gnome org>]

commit 3e1c014ca4faeb5c5682e3a90402edc84c41ab5b
Author: Florian MÃllner <fmuellner gnome org>
Date:   Wed May 16 02:18:57 2012 +0200

    configure: Add missing AC_ARG_VAR
    
    I missed that in the review of commit 9375ce07, sorry.

 configure.ac |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 998d375..30374f5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -158,6 +158,7 @@ fi
 #   AC_MSG_ERROR([gtk-builder-convert not found])
 # fi
 
+AC_ARG_VAR([XMLLINT],[the xmllint programme])
 AC_PATH_PROG([XMLLINT],[xmllint],[false])
 if test "$XMLLINT" = "false"; then
   AC_MSG_ERROR([xmllint not found])