prevent UI test failure randomly

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@11978 e93f8b46-1217-0410-a6f0-8f06a7374b81
not run Capybara tests on the CI server (#12822)

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@11979 e93f8b46-1217-0410-a6f0-8f06a7374b81