[mutter/gnome-3-28] monitor-manager: Add back warning messages

[Marco Trevisan <marcotrevi src gnome org>]

commit ca71b0eb1a806bde3c0f3b2b8098995f57e0defc
Author: Jonas Ådahl <jadahl gmail com>
Date:   Tue Apr 24 15:25:56 2018 +0200

    monitor-manager: Add back warning messages
    
    For some reason "backends: Remove X11 idle-monitor backend" removed
    unrelated warning messages for when generated monitor configurations
    that should work didn't, which also made the unit tests fail.
    
    This commit adds them back, which also makes the tests pass again.
    
    
    (cherry picked from commit d9c18fd5bbd6b06453bb06a64eb8b31866d2f963)

 src/backends/meta-monitor-manager.c | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/src/backends/meta-monitor-manager.c b/src/backends/meta-monitor-manager.c
index 6d9e2ade4..5bd34ad47 100644
--- a/src/backends/meta-monitor-manager.c
+++ b/src/backends/meta-monitor-manager.c
@@ -585,6 +585,8 @@ meta_monitor_manager_ensure_configured (MetaMonitorManager *manager)
                                                        &error))
         {
           g_clear_object (&config);
+          g_warning ("Failed to use linear monitor configuration: %s",
+                     error->message);
           g_clear_error (&error);
         }
       else
@@ -602,6 +604,8 @@ meta_monitor_manager_ensure_configured (MetaMonitorManager *manager)
                                                        &error))
         {
           g_clear_object (&config);
+          g_warning ("Failed to use fallback monitor configuration: %s",
+                     error->message);
           g_clear_error (&error);
         }
       else