Enable FOREIGN KEYS by default

src/ejabberd_odbc.erl

@@ -501,6 +501,7 @@ sqlite_connect(DB) ->
     process_flag(trap_exit, true),
     case sqlite3:open(?SQLITE_DB, [{file, binary_to_list(DB)}]) of
         {ok, Ref} ->
+	    sqlite3:sql_exec(?SQLITE_DB, "pragma foreign_keys = on"),
             {ok, Ref};
         {error, {already_started, Ref}} ->
             {ok, Ref};

src/ejabberd_odbc_sup.erl

@@ -143,6 +143,7 @@ check_sqlite_db(DB) ->
           end,
     case Ret of
         ok ->
+	    sqlite3:sql_exec(?SQLITE_DB, "pragma foreign_keys = on"),
             case sqlite3:list_tables(?SQLITE_DB) of
                 [] ->
                     create_sqlite_tables(),