SQLite: Bug creation new users

Not tested much yet. Some MySQL parts changed a bit too to double-check.
https://github.com/marienfressinaud/FreshRSS/issues/574

app/SQL/install.sql.sqlite.php

@@ -1,4 +1,5 @@
 <?php
+global $SQL_CREATE_TABLES;
 $SQL_CREATE_TABLES = array(
 'CREATE TABLE IF NOT EXISTS `%1$scategory` (
 	`id` INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,