[fix][admin] Fix exception thrown in getMessageId method (#23784)

Co-authored-by: houbonan <[email protected]>
(cherry picked from commit 1f7a79f)

pulsar-broker/src/main/java/org/apache/pulsar/broker/admin/impl/PersistentTopicsBase.java

@@ -2764,6 +2764,7 @@ public void readEntryFailed(ManagedLedgerException exception,
                             if (exception instanceof ManagedLedgerException.LedgerNotExistException) {
                                 results.completeExceptionally(
                                         new RestException(Status.NOT_FOUND, "Message id not found"));
+                                return;
                             }
                             results.completeExceptionally(new RestException(exception));
                         }