doctrine#6167 doctrine#6168 - clarifying on the reasoning why query…

… is used instead of `fetchColumn`

(cherry picked from commit d2be4a2)

lib/Doctrine/ORM/Id/SequenceGenerator.php

@@ -76,7 +76,7 @@ public function generate(EntityManager $em, $entity)
             $conn = $em->getConnection();
             $sql  = $conn->getDatabasePlatform()->getSequenceNextValSQL($this->_sequenceName);
 
-            // Use query to force master in MasterSlaveConnection
+            // Using `query` to force usage of the master server in MasterSlaveConnection
             $this->_nextValue = (int) $conn->query($sql)->fetchColumn();
             $this->_maxValue  = $this->_nextValue + $this->_allocationSize;
         }