tests: Add missing setlocale() call to file tests

This ensures that non-ASCII characters in the test output are printed
correctly in the logs.

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

gio/tests/file.c

@@ -1,3 +1,4 @@
+#include <locale.h>
 #include <string.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -3008,6 +3009,8 @@ test_build_attribute_list_for_copy (void)
 int
 main (int argc, char *argv[])
 {
+  setlocale (LC_ALL, "");
+
   g_test_init (&argc, &argv, NULL);
 
   g_test_add_func ("/file/basic", test_basic);