email_server: Use rollback journal for aliases sqlite DB

WAL journaling mode is causing problems with postfix unable to open the database
despite ownership and permission changes. Default is the DELETE rollback journal
mode. The former gives more performance but in our case, writes are very rare
and the DB is used mostly just for reads.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/modules/email_server/aliases.py

@@ -102,7 +102,6 @@ def first_setup():
 
     # Create schema if not exists
     query = '''
-PRAGMA journal_mode=WAL;
 BEGIN;
 CREATE TABLE IF NOT EXISTS alias (
     name TEXT NOT NULL,