Fix issues system tests by ensuring request completion (#43441).

Patch by Katsuya HIDAKA (user:hidakatsuya).


git-svn-id: https://svn.redmine.org/redmine/trunk@24130 e93f8b46-1217-0410-a6f0-8f06a7374b81

test/system/issues_test.rb

@@ -288,6 +288,7 @@ class IssuesSystemTest < ApplicationSystemTestCase
       first('#content span.icon-actions').click
       first('#content a.icon-del').click
     end
+    assert_selector 'h2', text: 'Confirmation'
   end
 
   def test_remove_issue_watcher_from_sidebar