[gnome-system-monitor] preferences: don't display the selinux column if it's not enabled/supported

[Robert Roth <robertroth src gnome org>]

commit d5584bb655e4ba9dd38b340f29812a5b9159c01c
Author: Antoine Jacoutot <ajacoutot gnome org>
Date:   Mon Dec 9 09:44:17 2013 +0100

    preferences: don't display the selinux column if it's not enabled/supported
    
    https://bugzilla.gnome.org/show_bug.cgi?id=720091

 src/prefsdialog.cpp |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/prefsdialog.cpp b/src/prefsdialog.cpp
index 2af0d74..401ad8a 100644
--- a/src/prefsdialog.cpp
+++ b/src/prefsdialog.cpp
@@ -9,6 +9,7 @@
 
 #include "cgroups.h"
 #include "proctable.h"
+#include "selinux.h"
 #include "settings-keys.h"
 #include "util.h"
 
@@ -183,6 +184,8 @@ create_field_page(GtkBuilder* builder, GtkWidget *tree, const gchar *widgetname)
         column_id = gtk_tree_view_column_get_sort_column_id(column);
         if ((column_id == COL_CGROUP) && (!cgroups_enabled()))
             continue;
+        if ((column_id == COL_SECURITYCONTEXT) && (!can_show_security_context_column ()))
+            continue;
 
         if ((column_id == COL_UNIT ||
              column_id == COL_SESSION ||