Optimize PDO escape_str()
diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
index 3197e75..d18720e 100644
--- a/system/database/drivers/pdo/pdo_driver.php
+++ b/system/database/drivers/pdo/pdo_driver.php
@@ -264,7 +264,7 @@
 		$str = $this->conn_id->quote($str);
 
 		// If there are duplicated quotes, trim them away
-		if (strpos($str, "'") === 0)
+		if ($str[0] === "'")
 		{
 			$str = substr($str, 1, -1);
 		}