fix logo width

Before:

![owncloud_uygulamayonetici1](https://cloud.githubusercontent.com/assets/231068/3081850/69ace900-e4c7-11e3-80ba-2cd24c47e0ae.png)

After:

![owncloud_uygulamayonetici1](https://cloud.githubusercontent.com/assets/231068/3081856/77a20eaa-e4c7-11e3-9e84-61ee26334729.png)

@jancborchardt