Fixed that 200 API responses have a body containing one space (#11388).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@9975 e93f8b46-1217-0410-a6f0-8f06a7374b81

test/integration/api_test/issue_relations_test.rb

@@ -99,6 +99,7 @@ class ApiTest::IssueRelationsTest < ActionController::IntegrationTest
         end
 
         assert_response :ok
+        assert_equal '', @response.body
         assert_nil IssueRelation.find_by_id(2)
       end
     end