Make sure selected investment is visibile in spec

After changing the order for budget investments, the selected investment
didn't appear on the first page anymore, and so it couldn't be clicked
on during the test.

spec/features/admin/budget_investments_spec.rb

@@ -1126,18 +1126,22 @@ feature 'Admin budget investments' do
       end
     end
 
-    scenario "Pagination after unselecting an investment", :js do
+    feature "Pagination" do
-      create_list(:budget_investment, 30, budget: budget)
+      background { selected_bi.update(cached_votes_up: 50) }
 
-      visit admin_budget_budget_investments_path(budget)
+      scenario "After unselecting an investment", :js do
+        create_list(:budget_investment, 30, budget: budget)
 
-      within("#budget_investment_#{selected_bi.id}") do
+        visit admin_budget_budget_investments_path(budget)
-        click_link('Selected')
+
+        within("#budget_investment_#{selected_bi.id}") do
+          click_link('Selected')
+        end
+
+        click_link('Next')
+
+        expect(page).to have_link('Previous')
       end
-
-      click_link('Next')
-
-      expect(page).to have_link('Previous')
     end
   end