Add fallback for unthreaded telegram message

bridge/telegram/telegram.go

@@ -1,6 +1,7 @@
 package btelegram
 
 import (
+	"fmt"
 	"html"
 	"log"
 	"strconv"
@@ -108,6 +109,12 @@ func (b *Btelegram) Send(msg config.Message) (string, error) {
 		return b.handleDelete(&msg, chatid)
 	}
 
+	// Handle prefix hint for unthreaded messages.
+	if msg.ParentNotFound() {
+		msg.ParentID = ""
+		msg.Text = fmt.Sprintf("[reply]: %s", msg.Text)
+	}
+
 	// Upload a file if it exists
 	if msg.Extra != nil {
 		for _, rmsg := range helper.HandleExtra(&msg, b.General) {