[balsa] Build with gtk version < 3.12

[Peter Bloomfield <peterb src gnome org>]

commit fa51eff6ec9110a520d5c65811f9ee716beb5138
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Tue Jun 13 00:26:22 2017 -0400

    Build with gtk version < 3.12
    
        * src/filter-run-dialog.c (balsa_filter_run_dialog_new): build
        with gtk version < 3.12.

 ChangeLog               |    5 +++++
 src/filter-run-dialog.c |    4 +++-
 2 files changed, 8 insertions(+), 1 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 7efa87a..59b21fa 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2017-06-13  Peter Bloomfield  <pbloomfield bellsouth net>
+
+       * src/filter-run-dialog.c (balsa_filter_run_dialog_new): build
+       with gtk version < 3.12.
+
 2017-06-12  Peter Bloomfield  <pbloomfield bellsouth net>
 
        Use a wrapper for an environment variable
diff --git a/src/filter-run-dialog.c b/src/filter-run-dialog.c
index 4b17b0b..85967ef 100644
--- a/src/filter-run-dialog.c
+++ b/src/filter-run-dialog.c
@@ -179,11 +179,13 @@ balsa_filter_run_dialog_new(LibBalsaMailbox * mbox, GtkWindow * parent)
 {
     BalsaFilterRunDialog *p;
     gchar * dialog_title;
-    gboolean use_headerbar;
+    gboolean use_headerbar = TRUE;
 
     g_return_val_if_fail(mbox, NULL);
 
+#if GTK_CHECK_VERSION(3, 12, 0)
     use_headerbar = (libbalsa_dialog_flags() & GTK_DIALOG_USE_HEADER_BAR) != 0;
+#endif
     p = g_object_new(BALSA_TYPE_FILTER_RUN_DIALOG,
                      "transient-for", parent,
                      "use-header-bar", use_headerbar,