fix cucas authen, the old code work on 2.1.2 but not 1.9.2
fix cucas authen, the old code work on 2.1.2 but not 1.9.2

--HG--
branch : java

jittat/cafe-grader-web,cafe-grader-team/cafe-grader-web,jittat/cafe-grader-web,cafe-grader-team/cafe-grader-web,nattee/cafe-grader-web,nattee/cafe-grader-web,nattee/cafe-grader-web,cafe-grader-team/cafe-grader-web,nattee/cafe-grader-web,cafe-grader-team/cafe-grader-web