[#34077] Problem if feed contains only a few entries

#### How to test

1. create new newsfeed with https://jobwelt.telekom.com/jpapps/n/ext/rs/?query=t&keywords=TSIonsiteHH
2. Tab "Display" --> Number of Articles = 5 (or simple more than your newsfeed has)
3. create a menu entry for the newsfeed
4. Access the newsfeed on the frontend.
5. See the errors:

```
"Notice: Undefined offset: 1 in \htdocs\libraries\joomla\feed\feed.php on line 201"
```
and

```
"Notice: Trying to get property of non-object in \htdocs\components\com_newsfeeds\views\newsfeed\tmpl\default.php on line 109".
```
6. apply this patch e.g. with com_patchtester.
Documentation: http://docs.joomla.org/Component_Patchtester_for_Testers
Download: https://github.com/mbabker/patchtester/releases

7. See that the errors are gone.

### Tracker
http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_id=8103&tracker_item_id=34077