remove "OK Lab" from map markers

Before:
![untrimmed](https://cloud.githubusercontent.com/assets/245432/2840868/c9542392-d05d-11e3-9e9d-736d6714d21a.png)

After:
![trimmed](https://cloud.githubusercontent.com/assets/245432/2840866/c346b0aa-d05d-11e3-81a8-fc845352dda6.png)

@juliakloiber @fotografiona Eure Meinung dazu?