Fixed some warnings printed out during unit test

The following warnings were launched during UnitTest on certain eZ5 installations:

```
PHP Notice:  Undefined index: REQUEST_METHOD in .../ezpublish_legacy/extension/ezformtoken/event/ezxformtoken.php on line 116
```

```
PHP Warning:  strpos(): Empty delimiter in .../ezpublish_legacy/lib/ezutils/classes/ezsys.php on line 1209
```