Fix race condition that may segfault

src/iridium-markdown.c

@@ -64,8 +64,8 @@ iridium_markdown_compile_async (IridiumMarkdown *self,
   GTask *task;
 
   task = g_task_new (self, cancellable, callback, user_data);
-  g_task_run_in_thread (task, compile_thread);
   g_task_set_task_data (task, g_strdup (markdown), g_free);
+  g_task_run_in_thread (task, compile_thread);
   g_object_unref (task);
 }