Bump Cosmos API to 1.21.8 and replace empty AutoSell help message with configurable value

src/main/java/com/alttd/commands/subcommands/CommandAutoSell.java

@@ -125,6 +125,6 @@ public class CommandAutoSell extends SubCommand {
 
     @Override
     public String getHelpMessage() {
-        return "";
+        return Config.AUTO_SELL_MESSAGE;
     }
 }