SPIGOT-469: Add nag message for using (buggy) reload command.

By: md_5 <git@md-5.net>

paper-api/src/main/java/org/bukkit/command/defaults/ReloadCommand.java

@@ -20,6 +20,8 @@ public class ReloadCommand extends BukkitCommand {
     public boolean execute(CommandSender sender, String currentAlias, String[] args) {
         if (!testPermission(sender)) return true;
 
+        Command.broadcastCommandMessage(sender, ChatColor.RED + "Please note that this command is not supported and may cause issues when using some plugins.");
+        Command.broadcastCommandMessage(sender, ChatColor.RED + "If you encounter any issues please use the /stop command to restart your server.");
         Bukkit.reload();
         Command.broadcastCommandMessage(sender, ChatColor.GREEN + "Reload complete.");