[gthumb] use GTK_STYLE_CLASS_SUGGESTED_ACTION only if defined

[Paolo Bacchilega <paobac src gnome org>]

commit 9893f3975b48063057846b99aa5e739362de31d0
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Sun Jan 18 17:03:58 2015 +0100

    use GTK_STYLE_CLASS_SUGGESTED_ACTION only if defined

 gthumb/gth-browser.c |    2 ++
 gthumb/gth-toolbox.c |    2 ++
 2 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/gthumb/gth-browser.c b/gthumb/gth-browser.c
index 6c6c900..45e4296 100644
--- a/gthumb/gth-browser.c
+++ b/gthumb/gth-browser.c
@@ -4399,7 +4399,9 @@ gth_browser_init (GthBrowser *browser)
                                                                  NULL,
                                                                  "win.apply-editor-changes",
                                                                  NULL);
+#ifdef GTK_STYLE_CLASS_SUGGESTED_ACTION
                gtk_style_context_add_class (gtk_widget_get_style_context (button), 
GTK_STYLE_CLASS_SUGGESTED_ACTION);
+#endif
        }
 
        /* fullscreen toolbar */
diff --git a/gthumb/gth-toolbox.c b/gthumb/gth-toolbox.c
index 3edaca9..9f910cd 100644
--- a/gthumb/gth-toolbox.c
+++ b/gthumb/gth-toolbox.c
@@ -238,7 +238,9 @@ gth_toolbox_init (GthToolbox *toolbox)
        g_signal_connect (close_button, "clicked", G_CALLBACK (close_button_clicked_cb), toolbox);
 
        ok_button = gtk_button_new_from_icon_name ("object-select-symbolic", GTK_ICON_SIZE_BUTTON);
+#ifdef GTK_STYLE_CLASS_SUGGESTED_ACTION
        gtk_style_context_add_class (gtk_widget_get_style_context (ok_button), 
GTK_STYLE_CLASS_SUGGESTED_ACTION);
+#endif
        gtk_widget_show (ok_button);
        g_signal_connect (ok_button, "clicked", G_CALLBACK (ok_button_clicked_cb), toolbox);