[libxml++] Require libxml2 2.7.7 or later

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 7e3bafca07331f2fea3169d3ad6d056504fd4b6d
Author: Kjell Ahlstedt <kjell ahlstedt bredband net>
Date:   Wed Mar 4 09:30:02 2015 +0100

    Require libxml2 2.7.7 or later
    
    * configure.ac: Require libxml2 2.7.7 or later. Earlier versions contain a
    bug that makes some of the example programs crash.

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index b9fd0c9..fe880bf 100644
--- a/configure.ac
+++ b/configure.ac
@@ -28,7 +28,7 @@ AC_PROG_CXX
 LT_PREREQ([2.2.6])
 LT_INIT([dlopen win32-dll disable-static])
 
-AC_SUBST([LIBXMLXX_MODULES], ['libxml-2.0 >= 2.7.3 glibmm-2.4 >= 2.32.0'])
+AC_SUBST([LIBXMLXX_MODULES], ['libxml-2.0 >= 2.7.7 glibmm-2.4 >= 2.32.0'])
 PKG_CHECK_MODULES([LIBXMLXX], [$LIBXMLXX_MODULES])
 
 AC_LANG([C++])