[ticket/17296] Enforce unique session entry for admin user with delete

PHPBB3-17296

tests/functional/session_page_update_test.php

@@ -25,16 +25,17 @@ public function setUp(): void
 
 		$db = $this->db;
 
+		// Delete previous session info for admin user
+		$sql = 'DELETE FROM ' . SESSIONS_TABLE . ' WHERE session_user_id = 2';
+		$db->sql_query($sql);
+
 		$this->login();
 	}
 
 	public function test_session_page_update()
 	{
 		$db = $this->get_db();
 
-		// Sleep for 2 seconds to ensure we don't have session time race condition
-		sleep(2);
-
 		// Request index page
 		self::request('GET', 'index.php');
 		$this->assertEquals(200, self::$client->getResponse()->getStatus());