[gnome-control-center] display-panel: Clear the variant builder if not showing an OSD

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit ca884dc666a59f8fd236b84413fe96f08215b5a9
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Fri May 28 22:59:24 2021 +0200

    display-panel: Clear the variant builder if not showing an OSD
    
    When we've only one monitor active we are not showing the OSD but we're
    leaking the variant used to request the shell to show the OSDs.

 panels/display/cc-display-panel.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/panels/display/cc-display-panel.c b/panels/display/cc-display-panel.c
index 93c983f89..f9d4ae044 100644
--- a/panels/display/cc-display-panel.c
+++ b/panels/display/cc-display-panel.c
@@ -382,7 +382,10 @@ monitor_labeler_show (CcDisplayPanel *self)
   g_variant_builder_close (&builder);
 
   if (number < 2)
-    return monitor_labeler_hide (self);
+    {
+      g_variant_builder_clear (&builder);
+      return monitor_labeler_hide (self);
+    }
 
   g_dbus_proxy_call (self->shell_proxy,
                      "ShowMonitorLabels",