tests: Add setlocale() call to spawn-singlethread

This allows non-ASCII characters to be used in test messages from it.

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>

glib/tests/spawn-singlethread.c

@@ -24,6 +24,7 @@
 #include "config.h"
 
 #include <glib.h>
+#include <locale.h>
 #include <string.h>
 #include <fcntl.h>
 
@@ -427,6 +428,8 @@ main (int   argc,
   char *dirname;
   int ret;
 
+  setlocale (LC_ALL, "");
+
   g_test_init (&argc, &argv, NULL);
 
   dirname = g_path_get_dirname (argv[0]);