fixes chatbubble padding

frontend/src/conversation/Conversation.tsx

@@ -35,7 +35,7 @@ export default function Conversation() {
           return (
             <ConversationBubble
               ref={index === messages.length - 1 ? endMessageRef : null}
-              className="mb-7"
+              className={`${index === messages.length - 1 ? 'mb-20' : 'mb-7'}`}
               key={index}
               message={message.text}
               type={message.type}