headless: fix the output refresh rate

60 millihertz is a bit low, let's make it 60 Hz as it was supposed to
be.

When the new repaint scheduling algorithm gets implemented, this
fixes 'make check' taking almost 3 minutes instead of the normal 3
seconds, when running with 7 millisecond repaint window.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Daniel Stone <daniels@collabora.com>

src/compositor-headless.c

@@ -128,7 +128,7 @@ headless_compositor_create_output(struct headless_compositor *c,
 		WL_OUTPUT_MODE_CURRENT | WL_OUTPUT_MODE_PREFERRED;
 	output->mode.width = param->width;
 	output->mode.height = param->height;
-	output->mode.refresh = 60;
+	output->mode.refresh = 60000;
 	wl_list_init(&output->base.mode_list);
 	wl_list_insert(&output->base.mode_list, &output->mode.link);