rdbms: Fix grammar in DBTransactionSizeError log message

Change-Id: Icc09d674359012f60494b95a36127c14c1a8d630

Author: AaronSchulz

includes/libs/rdbms/loadbalancer/LoadBalancer.php

@@ -1172,7 +1172,7 @@ public function approveMasterChanges( array $options ) {
 if ( $limit > 0 && $time > $limit ) {
 throw new DBTransactionSizeError(
 $conn,
-"Transaction spent $time second(s) in writes, exceeding the $limit limit.",
+"Transaction spent $time second(s) in writes, exceeding the limit of $limit.",
 [ $time, $limit ]
 );
 }