[gnome-flashback] backends: fix memory leak

[Alberts Muktupāvels <muktupavels src gnome org>]

commit f90eb97134557d7dd2a2011522d58fc3495d45cf
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Thu Mar 12 17:43:06 2020 +0200

    backends: fix memory leak

 backends/gf-monitor-manager.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)
---
diff --git a/backends/gf-monitor-manager.c b/backends/gf-monitor-manager.c
index deaf5cf..87be53c 100644
--- a/backends/gf-monitor-manager.c
+++ b/backends/gf-monitor-manager.c
@@ -2480,9 +2480,14 @@ gf_monitor_manager_ensure_configured (GfMonitorManager *manager)
 done:
   if (!config)
     {
-      gf_monitor_manager_apply_monitors_config (manager, NULL,
-                                                fallback_method,
-                                                &error);
+      if (!gf_monitor_manager_apply_monitors_config (manager, NULL,
+                                                     fallback_method,
+                                                     &error))
+        {
+          g_warning ("%s", error->message);
+          g_clear_error (&error);
+        }
+
       return NULL;
     }