Fixed elastic search params array

[wachterjohannes]

This PR fixes the config for elastisearch client constructor.

[danrot]

@wachterjohannes Is it possible to add a test in some way? Otherwise we won't detect it another time if something is going wrong.

[wachterjohannes]

@danrot how would you do that?

[danrot]

I don't know, that's why I am asking 😉