Fix LBTC API call for sending messages

handler/lib/localbitcoins_py.py

@@ -396,7 +396,7 @@ class LocalBitcoins:
         """
         payload = {"msg": msg}
         return self._api_call(
-            api_method=f"contact_message_post/{trade_id}/",
+            api_method=f"api/contact_message_post/{trade_id}/",
             http_method="POST",
             query_values=payload,
         )