Fix search integration-cli test

@unclejack, can you please take a look at this one. There is something weird.

Before the change, the test was not actually testing anything. It was calling `docker`, so it displayed the usage and looked for registry inside.

This test was the longest, I don't understand why.

Now I changed, it performs a search, this search is quite fast (only one result), but the test is still very long.

Do you have any idea ?