Fix registration check causing duplicate acks

Registration reminders are now sent as a unique message.
We also no longer perform a registration check on autocomplete requests

util/users.js

@@ -22,9 +22,8 @@ module.exports = {
             return true;
         }
 
-        interaction.reply({
-            content: `${interaction.member} You are not registered, use the /register command`,
-            ephemeral: false
+        interaction.channel.send({
+            content: `${interaction.member} You are not registered, use the /register command`
         });
         
         return false;