Fixed failure by increasing have at most value

1) advanced search pub info subject 'soviet union and historiography' and pub info '1910-1911 pub info 2010
     Failure/Error: resp.should have_at_most(138000).results
       expected at most 138000 results, got 138023
     # ./spec/advanced_search_spec.rb:340:in `block (4 levels) in <top (required)>'