zanran.js: increase signal

We want it to open if every other tab has a low signal. It doesn't even open up when it's the only answer available (other than images and video): https://duckduckgo.com/?q=agriculture+contribution+to+gdp

![screen shot 2014-12-02 at 3 48 19 pm](https://cloud.githubusercontent.com/assets/81969/5270658/0bfecbf2-7a3b-11e4-9704-dbe5e3dad096.png)