ui/gtk: Fix deprecation of vte_terminal_copy_clipboard

vte_terminal_copy_clipboard() is deprecated in VTE 0.50.

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
diff --git a/ui/gtk.c b/ui/gtk.c
index 5bd87c2..342e96f 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -1702,7 +1702,12 @@
     GtkDisplayState *s = opaque;
     VirtualConsole *vc = gd_vc_find_current(s);
 
+#if VTE_CHECK_VERSION(0, 50, 0)
+    vte_terminal_copy_clipboard_format(VTE_TERMINAL(vc->vte.terminal),
+                                       VTE_FORMAT_TEXT);
+#else
     vte_terminal_copy_clipboard(VTE_TERMINAL(vc->vte.terminal));
+#endif
 }
 
 static void gd_vc_adjustment_changed(GtkAdjustment *adjustment, void *opaque)