[HttpFoundation] Rename session expiry index

Author: nicolas-grekas

CHANGELOG.md

@@ -104,7 +104,7 @@ CHANGELOG
    make sure to run `ALTER TABLE sessions MODIFY sess_lifetime INTEGER UNSIGNED NOT NULL` to
    update your database.
  * `PdoSessionHandler` now precalculates the expiry timestamp in the lifetime column,
-    make sure to run `CREATE INDEX EXPIRY ON sessions (sess_lifetime)` to update your database
+    make sure to run `CREATE INDEX expiry ON sessions (sess_lifetime)` to update your database
     to speed up garbage collection of expired sessions.
  * added `SessionHandlerFactory` to create session handlers with a DSN
  * added `IpUtils::anonymize()` to help with GDPR compliance.

Session/Storage/Handler/PdoSessionHandler.php

@@ -207,7 +207,7 @@ public function createTable()
 
         try {
             $this->pdo->exec($sql);
-            $this->pdo->exec("CREATE INDEX EXPIRY ON $this->table ($this->lifetimeCol)");
+            $this->pdo->exec("CREATE INDEX expiry ON $this->table ($this->lifetimeCol)");
         } catch (\PDOException $e) {
             $this->rollback();