ensure bot doesn't reply to its own messages

src/bot.rs

@@ -210,6 +210,10 @@ impl Bot {
         ev: &OriginalRoomMessageEvent,
         room: &Joined,
     ) -> Result<()> {
+        if Some(&*ev.sender) == self.client.user_id() {
+            return Ok(());
+        }
+
         let MessageType::Text(TextMessageEventContent { body, .. }) = &ev.content.msgtype else {
             return Ok(());
         };