[vte] widget: Warn about CSS problem with upgrade to gtk 3.19

[Christian Persch <chpe src gnome org>]

commit fa008f96d9484204db73d2b500f22f47c247905e
Author: Christian Persch <chpe gnome org>
Date:   Mon Mar 14 18:07:35 2016 +0100

    widget: Warn about CSS problem with upgrade to gtk 3.19
    
    https://bugzilla.gnome.org/show_bug.cgi?id=763538

 src/vtegtk.cc |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/src/vtegtk.cc b/src/vtegtk.cc
index ef92066..3079ffa 100644
--- a/src/vtegtk.cc
+++ b/src/vtegtk.cc
@@ -636,6 +636,10 @@ vte_terminal_class_init(VteTerminalClass *klass)
 
 #if GTK_CHECK_VERSION(3, 19, 5)
         gtk_widget_class_set_css_name(widget_class, VTE_TERMINAL_CSS_NAME);
+#else
+        /* Bug #763538 */
+        if (gtk_check_version(3, 19, 5) == nullptr)
+                g_printerr("VTE needs to be recompiled against a newer gtk+ version.\n");
 #endif
 
        /* Initialize default handlers. */