SDP-2102 fix: update broken SDP recipient_registration_attempts query

Author: hypekostas

docs/platforms/stellar-disbursement-platform/admin-guide/troubleshooting.mdx

@@ -249,7 +249,7 @@ The most frequent cause is the receiver entering a different email or phone numb
 
 ```sql
 SELECT * FROM sdp_<tenant_name>.receiver_registration_attempts
-ORDER BY created_at DESC
+ORDER BY attempt_ts DESC
 LIMIT 20;
 ```