[mutter] main: Warn instead of error in meta_test_init()

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

commit 69a0c1dc80ec733a807d61825e56794bdcf8c5ca
Author: Jonas Ådahl <jadahl gmail com>
Date:   Wed Oct 9 10:58:43 2019 +0200

    main: Warn instead of error in meta_test_init()
    
    Otherwise we'll get the warning
    
    ../src/core/main.c: In function 'meta_test_init':
    ../src/core/main.c:755:1: error: function might be candidate for attribute 'noreturn' 
[-Werror=suggest-attribute=noreturn]
      755 | meta_test_init (void)
          | ^~~~~~~~~~~~~~
    
    when building without Wayland.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/837

 src/core/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/core/main.c b/src/core/main.c
index 7f4f666d2..3935f3523 100644
--- a/src/core/main.c
+++ b/src/core/main.c
@@ -766,6 +766,6 @@ meta_test_init (void)
 
   close (fd);
 #else
-  g_error ("Tests require wayland support");
+  g_warning ("Tests require wayland support");
 #endif
 }