[gnote] Fix build on some systems

[Aurimas Äernius <aurimasc src gnome org>]

commit 6769947c7fdce72ae1f51b227253180e23845b95
Author: Aurimas Äernius <aurisc4 gmail com>
Date:   Mon Jul 16 23:03:48 2012 +0300

    Fix build on some systems
    
    Add check for X11.
    Fixes bug 679496.
    Thanks Olav Vitters.

 configure.ac |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 0f09770..67ff37f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -64,6 +64,7 @@ AC_LANG_COMPILER_REQUIRE
 
 PKG_CHECK_MODULES(LIBGLIBMM, [glibmm-2.4])
 PKG_CHECK_MODULES(GTK, [gtk+-3.0 >= $GTK_VERSION])
+PKG_CHECK_MODULES(X, [x11])
 PKG_CHECK_MODULES(LIBGTKMM, [gtkmm-3.0 >= $LIBGTKMM_VERSION])
 # Check for glib 2.32 or higher, which have certain incompatibilities with older ones
 PKG_CHECK_EXISTS(glib-2.0 >= 2.32,